date.c

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/*-------------------------------------------------------------------------
 *
 * date.c
 *    implements DATE and TIME data types specified in SQL standard
 *
 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994-5, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/utils/adt/date.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include <ctype.h>
#include <limits.h>
#include <float.h>
#include <time.h>

#include "access/xact.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "nodes/supportnodes.h"
#include "parser/scansup.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/datetime.h"
#include "utils/hashutils.h"
#include "utils/sortsupport.h"

/*
 * gcc's -ffast-math switch breaks routines that expect exact results from
 * expressions like timeval / SECS_PER_HOUR, where timeval is double.
 */
#ifdef __FAST_MATH__
#error -ffast-math is known to break this code
#endif


/* common code for timetypmodin and timetztypmodin */
static int32
anytime_typmodin(bool istz, ArrayType *ta)
{
    int32      *tl;
    int         n;

    tl = ArrayGetIntegerTypmods(ta, &n);

    /*
     * we're not too tense about good error message here because grammar
     * shouldn't allow wrong number of modifiers for TIME
     */
    if (n != 1)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid type modifier")));

    return anytime_typmod_check(istz, tl[0]);
}

/* exported so parse_expr.c can use it */
int32
anytime_typmod_check(bool istz, int32 typmod)
{
    if (typmod < 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("TIME(%d)%s precision must not be negative",
                        typmod, (istz ? " WITH TIME ZONE" : ""))));
    if (typmod > MAX_TIME_PRECISION)
    {
        ereport(WARNING,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("TIME(%d)%s precision reduced to maximum allowed, %d",
                        typmod, (istz ? " WITH TIME ZONE" : ""),
                        MAX_TIME_PRECISION)));
        typmod = MAX_TIME_PRECISION;
    }

    return typmod;
}

/* common code for timetypmodout and timetztypmodout */
static char *
anytime_typmodout(bool istz, int32 typmod)
{
    const char *tz = istz ? " with time zone" : " without time zone";

    if (typmod >= 0)
        return psprintf("(%d)%s", (int) typmod, tz);
    else
        return psprintf("%s", tz);
}


/*****************************************************************************
 *   Date ADT
 *****************************************************************************/


/* date_in()
 * Given date text string, convert to internal date format.
 */
Datum
date_in(PG_FUNCTION_ARGS)
{
    char       *str = PG_GETARG_CSTRING(0);
    DateADT     date;
    fsec_t      fsec;
    struct pg_tm tt,
               *tm = &tt;
    int         tzp;
    int         dtype;
    int         nf;
    int         dterr;
    char       *field[MAXDATEFIELDS];
    int         ftype[MAXDATEFIELDS];
    char        workbuf[MAXDATELEN + 1];

    dterr = ParseDateTime(str, workbuf, sizeof(workbuf),
                          field, ftype, MAXDATEFIELDS, &nf);
    if (dterr == 0)
        dterr = DecodeDateTime(field, ftype, nf, &dtype, tm, &fsec, &tzp);
    if (dterr != 0)
        DateTimeParseError(dterr, str, "date");

    switch (dtype)
    {
        case DTK_DATE:
            break;

        case DTK_EPOCH:
            GetEpochTime(tm);
            break;

        case DTK_LATE:
            DATE_NOEND(date);
            PG_RETURN_DATEADT(date);

        case DTK_EARLY:
            DATE_NOBEGIN(date);
            PG_RETURN_DATEADT(date);

        default:
            DateTimeParseError(DTERR_BAD_FORMAT, str, "date");
            break;
    }

    /* Prevent overflow in Julian-day routines */
    if (!IS_VALID_JULIAN(tm->tm_year, tm->tm_mon, tm->tm_mday))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: \"%s\"", str)));

    date = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;

    /* Now check for just-out-of-range dates */
    if (!IS_VALID_DATE(date))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: \"%s\"", str)));

    PG_RETURN_DATEADT(date);
}

/* date_out()
 * Given internal format date, convert to text string.
 */
Datum
date_out(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    char       *result;
    struct pg_tm tt,
               *tm = &tt;
    char        buf[MAXDATELEN + 1];

    if (DATE_NOT_FINITE(date))
        EncodeSpecialDate(date, buf);
    else
    {
        j2date(date + POSTGRES_EPOCH_JDATE,
               &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
        EncodeDateOnly(tm, DateStyle, buf);
    }

    result = pstrdup(buf);
    PG_RETURN_CSTRING(result);
}

/*
 *      date_recv           - converts external binary format to date
 */
Datum
date_recv(PG_FUNCTION_ARGS)
{
    StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);
    DateADT     result;

    result = (DateADT) pq_getmsgint(buf, sizeof(DateADT));

    /* Limit to the same range that date_in() accepts. */
    if (DATE_NOT_FINITE(result))
         /* ok */ ;
    else if (!IS_VALID_DATE(result))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range")));

    PG_RETURN_DATEADT(result);
}

/*
 *      date_send           - converts date to binary format
 */
Datum
date_send(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    StringInfoData buf;

    pq_begintypsend(&buf);
    pq_sendint32(&buf, date);
    PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}

/*
 *      make_date           - date constructor
 */
Datum
make_date(PG_FUNCTION_ARGS)
{
    struct pg_tm tm;
    DateADT     date;
    int         dterr;
    bool        bc = false;

    tm.tm_year = PG_GETARG_INT32(0);
    tm.tm_mon = PG_GETARG_INT32(1);
    tm.tm_mday = PG_GETARG_INT32(2);

    /* Handle negative years as BC */
    if (tm.tm_year < 0)
    {
        bc = true;
        tm.tm_year = -tm.tm_year;
    }

    dterr = ValidateDate(DTK_DATE_M, false, false, bc, &tm);

    if (dterr != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_FIELD_OVERFLOW),
                 errmsg("date field value out of range: %d-%02d-%02d",
                        tm.tm_year, tm.tm_mon, tm.tm_mday)));

    /* Prevent overflow in Julian-day routines */
    if (!IS_VALID_JULIAN(tm.tm_year, tm.tm_mon, tm.tm_mday))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: %d-%02d-%02d",
                        tm.tm_year, tm.tm_mon, tm.tm_mday)));

    date = date2j(tm.tm_year, tm.tm_mon, tm.tm_mday) - POSTGRES_EPOCH_JDATE;

    /* Now check for just-out-of-range dates */
    if (!IS_VALID_DATE(date))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range: %d-%02d-%02d",
                        tm.tm_year, tm.tm_mon, tm.tm_mday)));

    PG_RETURN_DATEADT(date);
}

/*
 * Convert reserved date values to string.
 */
void
EncodeSpecialDate(DateADT dt, char *str)
{
    if (DATE_IS_NOBEGIN(dt))
        strcpy(str, EARLY);
    else if (DATE_IS_NOEND(dt))
        strcpy(str, LATE);
    else                        /* shouldn't happen */
        elog(ERROR, "invalid argument for EncodeSpecialDate");
}


/*
 * GetSQLCurrentDate -- implements CURRENT_DATE
 */
DateADT
GetSQLCurrentDate(void)
{
    TimestampTz ts;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;

    ts = GetCurrentTransactionStartTimestamp();

    if (timestamp2tm(ts, &tz, tm, &fsec, NULL, NULL) != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));

    return date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
}

/*
 * GetSQLCurrentTime -- implements CURRENT_TIME, CURRENT_TIME(n)
 */
TimeTzADT *
GetSQLCurrentTime(int32 typmod)
{
    TimeTzADT  *result;
    TimestampTz ts;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;

    ts = GetCurrentTransactionStartTimestamp();

    if (timestamp2tm(ts, &tz, tm, &fsec, NULL, NULL) != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
    tm2timetz(tm, fsec, tz, result);
    AdjustTimeForTypmod(&(result->time), typmod);
    return result;
}

/*
 * GetSQLLocalTime -- implements LOCALTIME, LOCALTIME(n)
 */
TimeADT
GetSQLLocalTime(int32 typmod)
{
    TimeADT     result;
    TimestampTz ts;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;

    ts = GetCurrentTransactionStartTimestamp();

    if (timestamp2tm(ts, &tz, tm, &fsec, NULL, NULL) != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));

    tm2time(tm, fsec, &result);
    AdjustTimeForTypmod(&result, typmod);
    return result;
}


/*
 * Comparison functions for dates
 */

Datum
date_eq(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_BOOL(dateVal1 == dateVal2);
}

Datum
date_ne(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_BOOL(dateVal1 != dateVal2);
}

Datum
date_lt(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_BOOL(dateVal1 < dateVal2);
}

Datum
date_le(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_BOOL(dateVal1 <= dateVal2);
}

Datum
date_gt(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_BOOL(dateVal1 > dateVal2);
}

Datum
date_ge(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_BOOL(dateVal1 >= dateVal2);
}

Datum
date_cmp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    if (dateVal1 < dateVal2)
        PG_RETURN_INT32(-1);
    else if (dateVal1 > dateVal2)
        PG_RETURN_INT32(1);
    PG_RETURN_INT32(0);
}

static int
date_fastcmp(Datum x, Datum y, SortSupport ssup)
{
    DateADT     a = DatumGetDateADT(x);
    DateADT     b = DatumGetDateADT(y);

    if (a < b)
        return -1;
    else if (a > b)
        return 1;
    return 0;
}

Datum
date_sortsupport(PG_FUNCTION_ARGS)
{
    SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);

    ssup->comparator = date_fastcmp;
    PG_RETURN_VOID();
}

Datum
date_finite(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);

    PG_RETURN_BOOL(!DATE_NOT_FINITE(date));
}

Datum
date_larger(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_DATEADT((dateVal1 > dateVal2) ? dateVal1 : dateVal2);
}

Datum
date_smaller(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    PG_RETURN_DATEADT((dateVal1 < dateVal2) ? dateVal1 : dateVal2);
}

/* Compute difference between two dates in days.
 */
Datum
date_mi(PG_FUNCTION_ARGS)
{
    DateADT     dateVal1 = PG_GETARG_DATEADT(0);
    DateADT     dateVal2 = PG_GETARG_DATEADT(1);

    if (DATE_NOT_FINITE(dateVal1) || DATE_NOT_FINITE(dateVal2))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("cannot subtract infinite dates")));

    PG_RETURN_INT32((int32) (dateVal1 - dateVal2));
}

/* Add a number of days to a date, giving a new date.
 * Must handle both positive and negative numbers of days.
 */
Datum
date_pli(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    int32       days = PG_GETARG_INT32(1);
    DateADT     result;

    if (DATE_NOT_FINITE(dateVal))
        PG_RETURN_DATEADT(dateVal); /* can't change infinity */

    result = dateVal + days;

    /* Check for integer overflow and out-of-allowed-range */
    if ((days >= 0 ? (result < dateVal) : (result > dateVal)) ||
        !IS_VALID_DATE(result))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range")));

    PG_RETURN_DATEADT(result);
}

/* Subtract a number of days from a date, giving a new date.
 */
Datum
date_mii(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    int32       days = PG_GETARG_INT32(1);
    DateADT     result;

    if (DATE_NOT_FINITE(dateVal))
        PG_RETURN_DATEADT(dateVal); /* can't change infinity */

    result = dateVal - days;

    /* Check for integer overflow and out-of-allowed-range */
    if ((days >= 0 ? (result > dateVal) : (result < dateVal)) ||
        !IS_VALID_DATE(result))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("date out of range")));

    PG_RETURN_DATEADT(result);
}


/*
 * Promote date to timestamp.
 *
 * If 'have_error' is NULL, then errors are thrown, else '*have_error' is set
 * and zero is returned.
 */
Timestamp
date2timestamp_opt_error(DateADT dateVal, bool *have_error)
{
    Timestamp   result;

    if (DATE_IS_NOBEGIN(dateVal))
        TIMESTAMP_NOBEGIN(result);
    else if (DATE_IS_NOEND(dateVal))
        TIMESTAMP_NOEND(result);
    else
    {
        /*
         * Date's range is wider than timestamp's, so check for boundaries.
         * Since dates have the same minimum values as timestamps, only upper
         * boundary need be checked for overflow.
         */
        if (dateVal >= (TIMESTAMP_END_JULIAN - POSTGRES_EPOCH_JDATE))
        {
            if (have_error)
            {
                *have_error = true;
                return (Timestamp) 0;
            }
            else
            {
                ereport(ERROR,
                        (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                         errmsg("date out of range for timestamp")));
            }
        }

        /* date is days since 2000, timestamp is microseconds since same... */
        result = dateVal * USECS_PER_DAY;
    }

    return result;
}

/*
 * Single-argument version of date2timestamp_opt_error().
 */
static TimestampTz
date2timestamp(DateADT dateVal)
{
    return date2timestamp_opt_error(dateVal, NULL);
}

/*
 * Promote date to timestamp with time zone.
 *
 * If 'have_error' is NULL, then errors are thrown, else '*have_error' is set
 * and zero is returned.
 */
TimestampTz
date2timestamptz_opt_error(DateADT dateVal, bool *have_error)
{
    TimestampTz result;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;

    if (DATE_IS_NOBEGIN(dateVal))
        TIMESTAMP_NOBEGIN(result);
    else if (DATE_IS_NOEND(dateVal))
        TIMESTAMP_NOEND(result);
    else
    {
        /*
         * Date's range is wider than timestamp's, so check for boundaries.
         * Since dates have the same minimum values as timestamps, only upper
         * boundary need be checked for overflow.
         */
        if (dateVal >= (TIMESTAMP_END_JULIAN - POSTGRES_EPOCH_JDATE))
        {
            if (have_error)
            {
                *have_error = true;
                return (TimestampTz) 0;
            }
            else
            {
                ereport(ERROR,
                        (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                         errmsg("date out of range for timestamp")));
            }
        }

        j2date(dateVal + POSTGRES_EPOCH_JDATE,
               &(tm->tm_year), &(tm->tm_mon), &(tm->tm_mday));
        tm->tm_hour = 0;
        tm->tm_min = 0;
        tm->tm_sec = 0;
        tz = DetermineTimeZoneOffset(tm, session_timezone);

        result = dateVal * USECS_PER_DAY + tz * USECS_PER_SEC;

        /*
         * Since it is possible to go beyond allowed timestamptz range because
         * of time zone, check for allowed timestamp range after adding tz.
         */
        if (!IS_VALID_TIMESTAMP(result))
        {
            if (have_error)
            {
                *have_error = true;
                return (TimestampTz) 0;
            }
            else
            {
                ereport(ERROR,
                        (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                         errmsg("date out of range for timestamp")));
            }
        }
    }

    return result;
}

/*
 * Single-argument version of date2timestamptz_opt_error().
 */
static TimestampTz
date2timestamptz(DateADT dateVal)
{
    return date2timestamptz_opt_error(dateVal, NULL);
}

/*
 * date2timestamp_no_overflow
 *
 * This is chartered to produce a double value that is numerically
 * equivalent to the corresponding Timestamp value, if the date is in the
 * valid range of Timestamps, but in any case not throw an overflow error.
 * We can do this since the numerical range of double is greater than
 * that of non-erroneous timestamps.  The results are currently only
 * used for statistical estimation purposes.
 */
double
date2timestamp_no_overflow(DateADT dateVal)
{
    double      result;

    if (DATE_IS_NOBEGIN(dateVal))
        result = -DBL_MAX;
    else if (DATE_IS_NOEND(dateVal))
        result = DBL_MAX;
    else
    {
        /* date is days since 2000, timestamp is microseconds since same... */
        result = dateVal * (double) USECS_PER_DAY;
    }

    return result;
}


/*
 * Crosstype comparison functions for dates
 */

Datum
date_eq_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
    Timestamp   dt1;

    dt1 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) == 0);
}

Datum
date_ne_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
    Timestamp   dt1;

    dt1 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) != 0);
}

Datum
date_lt_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
    Timestamp   dt1;

    dt1 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) < 0);
}

Datum
date_gt_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
    Timestamp   dt1;

    dt1 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) > 0);
}

Datum
date_le_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
    Timestamp   dt1;

    dt1 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) <= 0);
}

Datum
date_ge_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
    Timestamp   dt1;

    dt1 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) >= 0);
}

Datum
date_cmp_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   dt2 = PG_GETARG_TIMESTAMP(1);
    Timestamp   dt1;

    dt1 = date2timestamp(dateVal);

    PG_RETURN_INT32(timestamp_cmp_internal(dt1, dt2));
}

Datum
date_eq_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz dt1;

    dt1 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) == 0);
}

Datum
date_ne_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz dt1;

    dt1 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) != 0);
}

Datum
date_lt_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz dt1;

    dt1 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) < 0);
}

Datum
date_gt_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz dt1;

    dt1 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) > 0);
}

Datum
date_le_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz dt1;

    dt1 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) <= 0);
}

Datum
date_ge_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz dt1;

    dt1 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) >= 0);
}

Datum
date_cmp_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz dt2 = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz dt1;

    dt1 = date2timestamptz(dateVal);

    PG_RETURN_INT32(timestamptz_cmp_internal(dt1, dt2));
}

Datum
timestamp_eq_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    Timestamp   dt2;

    dt2 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) == 0);
}

Datum
timestamp_ne_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    Timestamp   dt2;

    dt2 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) != 0);
}

Datum
timestamp_lt_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    Timestamp   dt2;

    dt2 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) < 0);
}

Datum
timestamp_gt_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    Timestamp   dt2;

    dt2 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) > 0);
}

Datum
timestamp_le_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    Timestamp   dt2;

    dt2 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) <= 0);
}

Datum
timestamp_ge_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    Timestamp   dt2;

    dt2 = date2timestamp(dateVal);

    PG_RETURN_BOOL(timestamp_cmp_internal(dt1, dt2) >= 0);
}

Datum
timestamp_cmp_date(PG_FUNCTION_ARGS)
{
    Timestamp   dt1 = PG_GETARG_TIMESTAMP(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    Timestamp   dt2;

    dt2 = date2timestamp(dateVal);

    PG_RETURN_INT32(timestamp_cmp_internal(dt1, dt2));
}

Datum
timestamptz_eq_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    TimestampTz dt2;

    dt2 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) == 0);
}

Datum
timestamptz_ne_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    TimestampTz dt2;

    dt2 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) != 0);
}

Datum
timestamptz_lt_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    TimestampTz dt2;

    dt2 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) < 0);
}

Datum
timestamptz_gt_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    TimestampTz dt2;

    dt2 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) > 0);
}

Datum
timestamptz_le_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    TimestampTz dt2;

    dt2 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) <= 0);
}

Datum
timestamptz_ge_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    TimestampTz dt2;

    dt2 = date2timestamptz(dateVal);

    PG_RETURN_BOOL(timestamptz_cmp_internal(dt1, dt2) >= 0);
}

Datum
timestamptz_cmp_date(PG_FUNCTION_ARGS)
{
    TimestampTz dt1 = PG_GETARG_TIMESTAMPTZ(0);
    DateADT     dateVal = PG_GETARG_DATEADT(1);
    TimestampTz dt2;

    dt2 = date2timestamptz(dateVal);

    PG_RETURN_INT32(timestamptz_cmp_internal(dt1, dt2));
}

/*
 * in_range support function for date.
 *
 * We implement this by promoting the dates to timestamp (without time zone)
 * and then using the timestamp-and-interval in_range function.
 */
Datum
in_range_date_interval(PG_FUNCTION_ARGS)
{
    DateADT     val = PG_GETARG_DATEADT(0);
    DateADT     base = PG_GETARG_DATEADT(1);
    Interval   *offset = PG_GETARG_INTERVAL_P(2);
    bool        sub = PG_GETARG_BOOL(3);
    bool        less = PG_GETARG_BOOL(4);
    Timestamp   valStamp;
    Timestamp   baseStamp;

    valStamp = date2timestamp(val);
    baseStamp = date2timestamp(base);

    return DirectFunctionCall5(in_range_timestamp_interval,
                               TimestampGetDatum(valStamp),
                               TimestampGetDatum(baseStamp),
                               IntervalPGetDatum(offset),
                               BoolGetDatum(sub),
                               BoolGetDatum(less));
}


/* Add an interval to a date, giving a new date.
 * Must handle both positive and negative intervals.
 *
 * We implement this by promoting the date to timestamp (without time zone)
 * and then using the timestamp plus interval function.
 */
Datum
date_pl_interval(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    Timestamp   dateStamp;

    dateStamp = date2timestamp(dateVal);

    return DirectFunctionCall2(timestamp_pl_interval,
                               TimestampGetDatum(dateStamp),
                               PointerGetDatum(span));
}

/* Subtract an interval from a date, giving a new date.
 * Must handle both positive and negative intervals.
 *
 * We implement this by promoting the date to timestamp (without time zone)
 * and then using the timestamp minus interval function.
 */
Datum
date_mi_interval(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    Timestamp   dateStamp;

    dateStamp = date2timestamp(dateVal);

    return DirectFunctionCall2(timestamp_mi_interval,
                               TimestampGetDatum(dateStamp),
                               PointerGetDatum(span));
}

/* date_timestamp()
 * Convert date to timestamp data type.
 */
Datum
date_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    Timestamp   result;

    result = date2timestamp(dateVal);

    PG_RETURN_TIMESTAMP(result);
}

/* timestamp_date()
 * Convert timestamp to date data type.
 */
Datum
timestamp_date(PG_FUNCTION_ARGS)
{
    Timestamp   timestamp = PG_GETARG_TIMESTAMP(0);
    DateADT     result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;

    if (TIMESTAMP_IS_NOBEGIN(timestamp))
        DATE_NOBEGIN(result);
    else if (TIMESTAMP_IS_NOEND(timestamp))
        DATE_NOEND(result);
    else
    {
        if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("timestamp out of range")));

        result = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
    }

    PG_RETURN_DATEADT(result);
}


/* date_timestamptz()
 * Convert date to timestamp with time zone data type.
 */
Datum
date_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     dateVal = PG_GETARG_DATEADT(0);
    TimestampTz result;

    result = date2timestamptz(dateVal);

    PG_RETURN_TIMESTAMP(result);
}


/* timestamptz_date()
 * Convert timestamp with time zone to date data type.
 */
Datum
timestamptz_date(PG_FUNCTION_ARGS)
{
    TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
    DateADT     result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;

    if (TIMESTAMP_IS_NOBEGIN(timestamp))
        DATE_NOBEGIN(result);
    else if (TIMESTAMP_IS_NOEND(timestamp))
        DATE_NOEND(result);
    else
    {
        if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("timestamp out of range")));

        result = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
    }

    PG_RETURN_DATEADT(result);
}


/*****************************************************************************
 *   Time ADT
 *****************************************************************************/

Datum
time_in(PG_FUNCTION_ARGS)
{
    char       *str = PG_GETARG_CSTRING(0);

#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    TimeADT     result;
    fsec_t      fsec;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    int         nf;
    int         dterr;
    char        workbuf[MAXDATELEN + 1];
    char       *field[MAXDATEFIELDS];
    int         dtype;
    int         ftype[MAXDATEFIELDS];

    dterr = ParseDateTime(str, workbuf, sizeof(workbuf),
                          field, ftype, MAXDATEFIELDS, &nf);
    if (dterr == 0)
        dterr = DecodeTimeOnly(field, ftype, nf, &dtype, tm, &fsec, &tz);
    if (dterr != 0)
        DateTimeParseError(dterr, str, "time");

    tm2time(tm, fsec, &result);
    AdjustTimeForTypmod(&result, typmod);

    PG_RETURN_TIMEADT(result);
}

/* tm2time()
 * Convert a tm structure to a time data type.
 */
int
tm2time(struct pg_tm *tm, fsec_t fsec, TimeADT *result)
{
    *result = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec)
               * USECS_PER_SEC) + fsec;
    return 0;
}

/* time2tm()
 * Convert time data type to POSIX time structure.
 *
 * For dates within the range of pg_time_t, convert to the local time zone.
 * If out of this range, leave as UTC (in practice that could only happen
 * if pg_time_t is just 32 bits) - thomas 97/05/27
 */
int
time2tm(TimeADT time, struct pg_tm *tm, fsec_t *fsec)
{
    tm->tm_hour = time / USECS_PER_HOUR;
    time -= tm->tm_hour * USECS_PER_HOUR;
    tm->tm_min = time / USECS_PER_MINUTE;
    time -= tm->tm_min * USECS_PER_MINUTE;
    tm->tm_sec = time / USECS_PER_SEC;
    time -= tm->tm_sec * USECS_PER_SEC;
    *fsec = time;
    return 0;
}

Datum
time_out(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    char       *result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    char        buf[MAXDATELEN + 1];

    time2tm(time, tm, &fsec);
    EncodeTimeOnly(tm, fsec, false, 0, DateStyle, buf);

    result = pstrdup(buf);
    PG_RETURN_CSTRING(result);
}

/*
 *      time_recv           - converts external binary format to time
 */
Datum
time_recv(PG_FUNCTION_ARGS)
{
    StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);

#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    TimeADT     result;

    result = pq_getmsgint64(buf);

    if (result < INT64CONST(0) || result > USECS_PER_DAY)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("time out of range")));

    AdjustTimeForTypmod(&result, typmod);

    PG_RETURN_TIMEADT(result);
}

/*
 *      time_send           - converts time to binary format
 */
Datum
time_send(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    StringInfoData buf;

    pq_begintypsend(&buf);
    pq_sendint64(&buf, time);
    PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}

Datum
timetypmodin(PG_FUNCTION_ARGS)
{
    ArrayType  *ta = PG_GETARG_ARRAYTYPE_P(0);

    PG_RETURN_INT32(anytime_typmodin(false, ta));
}

Datum
timetypmodout(PG_FUNCTION_ARGS)
{
    int32       typmod = PG_GETARG_INT32(0);

    PG_RETURN_CSTRING(anytime_typmodout(false, typmod));
}

/*
 *      make_time           - time constructor
 */
Datum
make_time(PG_FUNCTION_ARGS)
{
    int         tm_hour = PG_GETARG_INT32(0);
    int         tm_min = PG_GETARG_INT32(1);
    double      sec = PG_GETARG_FLOAT8(2);
    TimeADT     time;

    /* This should match the checks in DecodeTimeOnly */
    if (tm_hour < 0 || tm_min < 0 || tm_min > MINS_PER_HOUR - 1 ||
        sec < 0 || sec > SECS_PER_MINUTE ||
        tm_hour > HOURS_PER_DAY ||
    /* test for > 24:00:00 */
        (tm_hour == HOURS_PER_DAY && (tm_min > 0 || sec > 0)))
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_FIELD_OVERFLOW),
                 errmsg("time field value out of range: %d:%02d:%02g",
                        tm_hour, tm_min, sec)));

    /* This should match tm2time */
    time = (((tm_hour * MINS_PER_HOUR + tm_min) * SECS_PER_MINUTE)
            * USECS_PER_SEC) + rint(sec * USECS_PER_SEC);

    PG_RETURN_TIMEADT(time);
}


/* time_support()
 *
 * Planner support function for the time_scale() and timetz_scale()
 * length coercion functions (we need not distinguish them here).
 */
Datum
time_support(PG_FUNCTION_ARGS)
{
    Node       *rawreq = (Node *) PG_GETARG_POINTER(0);
    Node       *ret = NULL;

    if (IsA(rawreq, SupportRequestSimplify))
    {
        SupportRequestSimplify *req = (SupportRequestSimplify *) rawreq;

        ret = TemporalSimplify(MAX_TIME_PRECISION, (Node *) req->fcall);
    }

    PG_RETURN_POINTER(ret);
}

/* time_scale()
 * Adjust time type for specified scale factor.
 * Used by PostgreSQL type system to stuff columns.
 */
Datum
time_scale(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    int32       typmod = PG_GETARG_INT32(1);
    TimeADT     result;

    result = time;
    AdjustTimeForTypmod(&result, typmod);

    PG_RETURN_TIMEADT(result);
}

/* AdjustTimeForTypmod()
 * Force the precision of the time value to a specified value.
 * Uses *exactly* the same code as in AdjustTimestampForTypmod()
 * but we make a separate copy because those types do not
 * have a fundamental tie together but rather a coincidence of
 * implementation. - thomas
 */
void
AdjustTimeForTypmod(TimeADT *time, int32 typmod)
{
    static const int64 TimeScales[MAX_TIME_PRECISION + 1] = {
        INT64CONST(1000000),
        INT64CONST(100000),
        INT64CONST(10000),
        INT64CONST(1000),
        INT64CONST(100),
        INT64CONST(10),
        INT64CONST(1)
    };

    static const int64 TimeOffsets[MAX_TIME_PRECISION + 1] = {
        INT64CONST(500000),
        INT64CONST(50000),
        INT64CONST(5000),
        INT64CONST(500),
        INT64CONST(50),
        INT64CONST(5),
        INT64CONST(0)
    };

    if (typmod >= 0 && typmod <= MAX_TIME_PRECISION)
    {
        if (*time >= INT64CONST(0))
            *time = ((*time + TimeOffsets[typmod]) / TimeScales[typmod]) *
                TimeScales[typmod];
        else
            *time = -((((-*time) + TimeOffsets[typmod]) / TimeScales[typmod]) *
                      TimeScales[typmod]);
    }
}


Datum
time_eq(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_BOOL(time1 == time2);
}

Datum
time_ne(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_BOOL(time1 != time2);
}

Datum
time_lt(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_BOOL(time1 < time2);
}

Datum
time_le(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_BOOL(time1 <= time2);
}

Datum
time_gt(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_BOOL(time1 > time2);
}

Datum
time_ge(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_BOOL(time1 >= time2);
}

Datum
time_cmp(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    if (time1 < time2)
        PG_RETURN_INT32(-1);
    if (time1 > time2)
        PG_RETURN_INT32(1);
    PG_RETURN_INT32(0);
}

Datum
time_hash(PG_FUNCTION_ARGS)
{
    return hashint8(fcinfo);
}

Datum
time_hash_extended(PG_FUNCTION_ARGS)
{
    return hashint8extended(fcinfo);
}

Datum
time_larger(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_TIMEADT((time1 > time2) ? time1 : time2);
}

Datum
time_smaller(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);

    PG_RETURN_TIMEADT((time1 < time2) ? time1 : time2);
}

/* overlaps_time() --- implements the SQL OVERLAPS operator.
 *
 * Algorithm is per SQL spec.  This is much harder than you'd think
 * because the spec requires us to deliver a non-null answer in some cases
 * where some of the inputs are null.
 */
Datum
overlaps_time(PG_FUNCTION_ARGS)
{
    /*
     * The arguments are TimeADT, but we leave them as generic Datums to avoid
     * dereferencing nulls (TimeADT is pass-by-reference!)
     */
    Datum       ts1 = PG_GETARG_DATUM(0);
    Datum       te1 = PG_GETARG_DATUM(1);
    Datum       ts2 = PG_GETARG_DATUM(2);
    Datum       te2 = PG_GETARG_DATUM(3);
    bool        ts1IsNull = PG_ARGISNULL(0);
    bool        te1IsNull = PG_ARGISNULL(1);
    bool        ts2IsNull = PG_ARGISNULL(2);
    bool        te2IsNull = PG_ARGISNULL(3);

#define TIMEADT_GT(t1,t2) \
    (DatumGetTimeADT(t1) > DatumGetTimeADT(t2))
#define TIMEADT_LT(t1,t2) \
    (DatumGetTimeADT(t1) < DatumGetTimeADT(t2))

    /*
     * If both endpoints of interval 1 are null, the result is null (unknown).
     * If just one endpoint is null, take ts1 as the non-null one. Otherwise,
     * take ts1 as the lesser endpoint.
     */
    if (ts1IsNull)
    {
        if (te1IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts1 = te1;
        te1IsNull = true;
    }
    else if (!te1IsNull)
    {
        if (TIMEADT_GT(ts1, te1))
        {
            Datum       tt = ts1;

            ts1 = te1;
            te1 = tt;
        }
    }

    /* Likewise for interval 2. */
    if (ts2IsNull)
    {
        if (te2IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts2 = te2;
        te2IsNull = true;
    }
    else if (!te2IsNull)
    {
        if (TIMEADT_GT(ts2, te2))
        {
            Datum       tt = ts2;

            ts2 = te2;
            te2 = tt;
        }
    }

    /*
     * At this point neither ts1 nor ts2 is null, so we can consider three
     * cases: ts1 > ts2, ts1 < ts2, ts1 = ts2
     */
    if (TIMEADT_GT(ts1, ts2))
    {
        /*
         * This case is ts1 < te2 OR te1 < te2, which may look redundant but
         * in the presence of nulls it's not quite completely so.
         */
        if (te2IsNull)
            PG_RETURN_NULL();
        if (TIMEADT_LT(ts1, te2))
            PG_RETURN_BOOL(true);
        if (te1IsNull)
            PG_RETURN_NULL();

        /*
         * If te1 is not null then we had ts1 <= te1 above, and we just found
         * ts1 >= te2, hence te1 >= te2.
         */
        PG_RETURN_BOOL(false);
    }
    else if (TIMEADT_LT(ts1, ts2))
    {
        /* This case is ts2 < te1 OR te2 < te1 */
        if (te1IsNull)
            PG_RETURN_NULL();
        if (TIMEADT_LT(ts2, te1))
            PG_RETURN_BOOL(true);
        if (te2IsNull)
            PG_RETURN_NULL();

        /*
         * If te2 is not null then we had ts2 <= te2 above, and we just found
         * ts2 >= te1, hence te2 >= te1.
         */
        PG_RETURN_BOOL(false);
    }
    else
    {
        /*
         * For ts1 = ts2 the spec says te1 <> te2 OR te1 = te2, which is a
         * rather silly way of saying "true if both are nonnull, else null".
         */
        if (te1IsNull || te2IsNull)
            PG_RETURN_NULL();
        PG_RETURN_BOOL(true);
    }

#undef TIMEADT_GT
#undef TIMEADT_LT
}

/* timestamp_time()
 * Convert timestamp to time data type.
 */
Datum
timestamp_time(PG_FUNCTION_ARGS)
{
    Timestamp   timestamp = PG_GETARG_TIMESTAMP(0);
    TimeADT     result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;

    if (TIMESTAMP_NOT_FINITE(timestamp))
        PG_RETURN_NULL();

    if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));

    /*
     * Could also do this with time = (timestamp / USECS_PER_DAY *
     * USECS_PER_DAY) - timestamp;
     */
    result = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec) *
              USECS_PER_SEC) + fsec;

    PG_RETURN_TIMEADT(result);
}

/* timestamptz_time()
 * Convert timestamptz to time data type.
 */
Datum
timestamptz_time(PG_FUNCTION_ARGS)
{
    TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
    TimeADT     result;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    fsec_t      fsec;

    if (TIMESTAMP_NOT_FINITE(timestamp))
        PG_RETURN_NULL();

    if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));

    /*
     * Could also do this with time = (timestamp / USECS_PER_DAY *
     * USECS_PER_DAY) - timestamp;
     */
    result = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec) *
              USECS_PER_SEC) + fsec;

    PG_RETURN_TIMEADT(result);
}

/* datetime_timestamp()
 * Convert date and time to timestamp data type.
 */
Datum
datetime_timestamp(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    TimeADT     time = PG_GETARG_TIMEADT(1);
    Timestamp   result;

    result = date2timestamp(date);
    if (!TIMESTAMP_NOT_FINITE(result))
    {
        result += time;
        if (!IS_VALID_TIMESTAMP(result))
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("timestamp out of range")));
    }

    PG_RETURN_TIMESTAMP(result);
}

/* time_interval()
 * Convert time to interval data type.
 */
Datum
time_interval(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    Interval   *result;

    result = (Interval *) palloc(sizeof(Interval));

    result->time = time;
    result->day = 0;
    result->month = 0;

    PG_RETURN_INTERVAL_P(result);
}

/* interval_time()
 * Convert interval to time data type.
 *
 * This is defined as producing the fractional-day portion of the interval.
 * Therefore, we can just ignore the months field.  It is not real clear
 * what to do with negative intervals, but we choose to subtract the floor,
 * so that, say, '-2 hours' becomes '22:00:00'.
 */
Datum
interval_time(PG_FUNCTION_ARGS)
{
    Interval   *span = PG_GETARG_INTERVAL_P(0);
    TimeADT     result;
    int64       days;

    result = span->time;
    if (result >= USECS_PER_DAY)
    {
        days = result / USECS_PER_DAY;
        result -= days * USECS_PER_DAY;
    }
    else if (result < 0)
    {
        days = (-result + USECS_PER_DAY - 1) / USECS_PER_DAY;
        result += days * USECS_PER_DAY;
    }

    PG_RETURN_TIMEADT(result);
}

/* time_mi_time()
 * Subtract two times to produce an interval.
 */
Datum
time_mi_time(PG_FUNCTION_ARGS)
{
    TimeADT     time1 = PG_GETARG_TIMEADT(0);
    TimeADT     time2 = PG_GETARG_TIMEADT(1);
    Interval   *result;

    result = (Interval *) palloc(sizeof(Interval));

    result->month = 0;
    result->day = 0;
    result->time = time1 - time2;

    PG_RETURN_INTERVAL_P(result);
}

/* time_pl_interval()
 * Add interval to time.
 */
Datum
time_pl_interval(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeADT     result;

    result = time + span->time;
    result -= result / USECS_PER_DAY * USECS_PER_DAY;
    if (result < INT64CONST(0))
        result += USECS_PER_DAY;

    PG_RETURN_TIMEADT(result);
}

/* time_mi_interval()
 * Subtract interval from time.
 */
Datum
time_mi_interval(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeADT     result;

    result = time - span->time;
    result -= result / USECS_PER_DAY * USECS_PER_DAY;
    if (result < INT64CONST(0))
        result += USECS_PER_DAY;

    PG_RETURN_TIMEADT(result);
}

/*
 * in_range support function for time.
 */
Datum
in_range_time_interval(PG_FUNCTION_ARGS)
{
    TimeADT     val = PG_GETARG_TIMEADT(0);
    TimeADT     base = PG_GETARG_TIMEADT(1);
    Interval   *offset = PG_GETARG_INTERVAL_P(2);
    bool        sub = PG_GETARG_BOOL(3);
    bool        less = PG_GETARG_BOOL(4);
    TimeADT     sum;

    /*
     * Like time_pl_interval/time_mi_interval, we disregard the month and day
     * fields of the offset.  So our test for negative should too.
     */
    if (offset->time < 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
                 errmsg("invalid preceding or following size in window function")));

    /*
     * We can't use time_pl_interval/time_mi_interval here, because their
     * wraparound behavior would give wrong (or at least undesirable) answers.
     * Fortunately the equivalent non-wrapping behavior is trivial, especially
     * since we don't worry about integer overflow.
     */
    if (sub)
        sum = base - offset->time;
    else
        sum = base + offset->time;

    if (less)
        PG_RETURN_BOOL(val <= sum);
    else
        PG_RETURN_BOOL(val >= sum);
}


/* time_part()
 * Extract specified field from time type.
 */
Datum
time_part(PG_FUNCTION_ARGS)
{
    text       *units = PG_GETARG_TEXT_PP(0);
    TimeADT     time = PG_GETARG_TIMEADT(1);
    float8      result;
    int         type,
                val;
    char       *lowunits;

    lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
                                            VARSIZE_ANY_EXHDR(units),
                                            false);

    type = DecodeUnits(0, lowunits, &val);
    if (type == UNKNOWN_FIELD)
        type = DecodeSpecial(0, lowunits, &val);

    if (type == UNITS)
    {
        fsec_t      fsec;
        struct pg_tm tt,
                   *tm = &tt;

        time2tm(time, tm, &fsec);

        switch (val)
        {
            case DTK_MICROSEC:
                result = tm->tm_sec * 1000000.0 + fsec;
                break;

            case DTK_MILLISEC:
                result = tm->tm_sec * 1000.0 + fsec / 1000.0;
                break;

            case DTK_SECOND:
                result = tm->tm_sec + fsec / 1000000.0;
                break;

            case DTK_MINUTE:
                result = tm->tm_min;
                break;

            case DTK_HOUR:
                result = tm->tm_hour;
                break;

            case DTK_TZ:
            case DTK_TZ_MINUTE:
            case DTK_TZ_HOUR:
            case DTK_DAY:
            case DTK_MONTH:
            case DTK_QUARTER:
            case DTK_YEAR:
            case DTK_DECADE:
            case DTK_CENTURY:
            case DTK_MILLENNIUM:
            case DTK_ISOYEAR:
            default:
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                         errmsg("\"time\" units \"%s\" not recognized",
                                lowunits)));
                result = 0;
        }
    }
    else if (type == RESERV && val == DTK_EPOCH)
    {
        result = time / 1000000.0;
    }
    else
    {
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"time\" units \"%s\" not recognized",
                        lowunits)));
        result = 0;
    }

    PG_RETURN_FLOAT8(result);
}


/*****************************************************************************
 *   Time With Time Zone ADT
 *****************************************************************************/

/* tm2timetz()
 * Convert a tm structure to a time data type.
 */
int
tm2timetz(struct pg_tm *tm, fsec_t fsec, int tz, TimeTzADT *result)
{
    result->time = ((((tm->tm_hour * MINS_PER_HOUR + tm->tm_min) * SECS_PER_MINUTE) + tm->tm_sec) *
                    USECS_PER_SEC) + fsec;
    result->zone = tz;

    return 0;
}

Datum
timetz_in(PG_FUNCTION_ARGS)
{
    char       *str = PG_GETARG_CSTRING(0);

#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    TimeTzADT  *result;
    fsec_t      fsec;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    int         nf;
    int         dterr;
    char        workbuf[MAXDATELEN + 1];
    char       *field[MAXDATEFIELDS];
    int         dtype;
    int         ftype[MAXDATEFIELDS];

    dterr = ParseDateTime(str, workbuf, sizeof(workbuf),
                          field, ftype, MAXDATEFIELDS, &nf);
    if (dterr == 0)
        dterr = DecodeTimeOnly(field, ftype, nf, &dtype, tm, &fsec, &tz);
    if (dterr != 0)
        DateTimeParseError(dterr, str, "time with time zone");

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
    tm2timetz(tm, fsec, tz, result);
    AdjustTimeForTypmod(&(result->time), typmod);

    PG_RETURN_TIMETZADT_P(result);
}

Datum
timetz_out(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    char       *result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;
    char        buf[MAXDATELEN + 1];

    timetz2tm(time, tm, &fsec, &tz);
    EncodeTimeOnly(tm, fsec, true, tz, DateStyle, buf);

    result = pstrdup(buf);
    PG_RETURN_CSTRING(result);
}

/*
 *      timetz_recv         - converts external binary format to timetz
 */
Datum
timetz_recv(PG_FUNCTION_ARGS)
{
    StringInfo  buf = (StringInfo) PG_GETARG_POINTER(0);

#ifdef NOT_USED
    Oid         typelem = PG_GETARG_OID(1);
#endif
    int32       typmod = PG_GETARG_INT32(2);
    TimeTzADT  *result;

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    result->time = pq_getmsgint64(buf);

    if (result->time < INT64CONST(0) || result->time > USECS_PER_DAY)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("time out of range")));

    result->zone = pq_getmsgint(buf, sizeof(result->zone));

    /* Check for sane GMT displacement; see notes in datatype/timestamp.h */
    if (result->zone <= -TZDISP_LIMIT || result->zone >= TZDISP_LIMIT)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_TIME_ZONE_DISPLACEMENT_VALUE),
                 errmsg("time zone displacement out of range")));

    AdjustTimeForTypmod(&(result->time), typmod);

    PG_RETURN_TIMETZADT_P(result);
}

/*
 *      timetz_send         - converts timetz to binary format
 */
Datum
timetz_send(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    StringInfoData buf;

    pq_begintypsend(&buf);
    pq_sendint64(&buf, time->time);
    pq_sendint32(&buf, time->zone);
    PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}

Datum
timetztypmodin(PG_FUNCTION_ARGS)
{
    ArrayType  *ta = PG_GETARG_ARRAYTYPE_P(0);

    PG_RETURN_INT32(anytime_typmodin(true, ta));
}

Datum
timetztypmodout(PG_FUNCTION_ARGS)
{
    int32       typmod = PG_GETARG_INT32(0);

    PG_RETURN_CSTRING(anytime_typmodout(true, typmod));
}


/* timetz2tm()
 * Convert TIME WITH TIME ZONE data type to POSIX time structure.
 */
int
timetz2tm(TimeTzADT *time, struct pg_tm *tm, fsec_t *fsec, int *tzp)
{
    TimeOffset  trem = time->time;

    tm->tm_hour = trem / USECS_PER_HOUR;
    trem -= tm->tm_hour * USECS_PER_HOUR;
    tm->tm_min = trem / USECS_PER_MINUTE;
    trem -= tm->tm_min * USECS_PER_MINUTE;
    tm->tm_sec = trem / USECS_PER_SEC;
    *fsec = trem - tm->tm_sec * USECS_PER_SEC;

    if (tzp != NULL)
        *tzp = time->zone;

    return 0;
}

/* timetz_scale()
 * Adjust time type for specified scale factor.
 * Used by PostgreSQL type system to stuff columns.
 */
Datum
timetz_scale(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    int32       typmod = PG_GETARG_INT32(1);
    TimeTzADT  *result;

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    result->time = time->time;
    result->zone = time->zone;

    AdjustTimeForTypmod(&(result->time), typmod);

    PG_RETURN_TIMETZADT_P(result);
}


static int
timetz_cmp_internal(TimeTzADT *time1, TimeTzADT *time2)
{
    TimeOffset  t1,
                t2;

    /* Primary sort is by true (GMT-equivalent) time */
    t1 = time1->time + (time1->zone * USECS_PER_SEC);
    t2 = time2->time + (time2->zone * USECS_PER_SEC);

    if (t1 > t2)
        return 1;
    if (t1 < t2)
        return -1;

    /*
     * If same GMT time, sort by timezone; we only want to say that two
     * timetz's are equal if both the time and zone parts are equal.
     */
    if (time1->zone > time2->zone)
        return 1;
    if (time1->zone < time2->zone)
        return -1;

    return 0;
}

Datum
timetz_eq(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) == 0);
}

Datum
timetz_ne(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) != 0);
}

Datum
timetz_lt(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) < 0);
}

Datum
timetz_le(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) <= 0);
}

Datum
timetz_gt(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) > 0);
}

Datum
timetz_ge(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

    PG_RETURN_BOOL(timetz_cmp_internal(time1, time2) >= 0);
}

Datum
timetz_cmp(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);

    PG_RETURN_INT32(timetz_cmp_internal(time1, time2));
}

Datum
timetz_hash(PG_FUNCTION_ARGS)
{
    TimeTzADT  *key = PG_GETARG_TIMETZADT_P(0);
    uint32      thash;

    /*
     * To avoid any problems with padding bytes in the struct, we figure the
     * field hashes separately and XOR them.
     */
    thash = DatumGetUInt32(DirectFunctionCall1(hashint8,
                                               Int64GetDatumFast(key->time)));
    thash ^= DatumGetUInt32(hash_uint32(key->zone));
    PG_RETURN_UINT32(thash);
}

Datum
timetz_hash_extended(PG_FUNCTION_ARGS)
{
    TimeTzADT  *key = PG_GETARG_TIMETZADT_P(0);
    Datum       seed = PG_GETARG_DATUM(1);
    uint64      thash;

    /* Same approach as timetz_hash */
    thash = DatumGetUInt64(DirectFunctionCall2(hashint8extended,
                                               Int64GetDatumFast(key->time),
                                               seed));
    thash ^= DatumGetUInt64(hash_uint32_extended(key->zone,
                                                 DatumGetInt64(seed)));
    PG_RETURN_UINT64(thash);
}

Datum
timetz_larger(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;

    if (timetz_cmp_internal(time1, time2) > 0)
        result = time1;
    else
        result = time2;
    PG_RETURN_TIMETZADT_P(result);
}

Datum
timetz_smaller(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time1 = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *time2 = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;

    if (timetz_cmp_internal(time1, time2) < 0)
        result = time1;
    else
        result = time2;
    PG_RETURN_TIMETZADT_P(result);
}

/* timetz_pl_interval()
 * Add interval to timetz.
 */
Datum
timetz_pl_interval(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeTzADT  *result;

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    result->time = time->time + span->time;
    result->time -= result->time / USECS_PER_DAY * USECS_PER_DAY;
    if (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;

    result->zone = time->zone;

    PG_RETURN_TIMETZADT_P(result);
}

/* timetz_mi_interval()
 * Subtract interval from timetz.
 */
Datum
timetz_mi_interval(PG_FUNCTION_ARGS)
{
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(0);
    Interval   *span = PG_GETARG_INTERVAL_P(1);
    TimeTzADT  *result;

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    result->time = time->time - span->time;
    result->time -= result->time / USECS_PER_DAY * USECS_PER_DAY;
    if (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;

    result->zone = time->zone;

    PG_RETURN_TIMETZADT_P(result);
}

/*
 * in_range support function for timetz.
 */
Datum
in_range_timetz_interval(PG_FUNCTION_ARGS)
{
    TimeTzADT  *val = PG_GETARG_TIMETZADT_P(0);
    TimeTzADT  *base = PG_GETARG_TIMETZADT_P(1);
    Interval   *offset = PG_GETARG_INTERVAL_P(2);
    bool        sub = PG_GETARG_BOOL(3);
    bool        less = PG_GETARG_BOOL(4);
    TimeTzADT   sum;

    /*
     * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
     * day fields of the offset.  So our test for negative should too.
     */
    if (offset->time < 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
                 errmsg("invalid preceding or following size in window function")));

    /*
     * We can't use timetz_pl_interval/timetz_mi_interval here, because their
     * wraparound behavior would give wrong (or at least undesirable) answers.
     * Fortunately the equivalent non-wrapping behavior is trivial, especially
     * since we don't worry about integer overflow.
     */
    if (sub)
        sum.time = base->time - offset->time;
    else
        sum.time = base->time + offset->time;
    sum.zone = base->zone;

    if (less)
        PG_RETURN_BOOL(timetz_cmp_internal(val, &sum) <= 0);
    else
        PG_RETURN_BOOL(timetz_cmp_internal(val, &sum) >= 0);
}

/* overlaps_timetz() --- implements the SQL OVERLAPS operator.
 *
 * Algorithm is per SQL spec.  This is much harder than you'd think
 * because the spec requires us to deliver a non-null answer in some cases
 * where some of the inputs are null.
 */
Datum
overlaps_timetz(PG_FUNCTION_ARGS)
{
    /*
     * The arguments are TimeTzADT *, but we leave them as generic Datums for
     * convenience of notation --- and to avoid dereferencing nulls.
     */
    Datum       ts1 = PG_GETARG_DATUM(0);
    Datum       te1 = PG_GETARG_DATUM(1);
    Datum       ts2 = PG_GETARG_DATUM(2);
    Datum       te2 = PG_GETARG_DATUM(3);
    bool        ts1IsNull = PG_ARGISNULL(0);
    bool        te1IsNull = PG_ARGISNULL(1);
    bool        ts2IsNull = PG_ARGISNULL(2);
    bool        te2IsNull = PG_ARGISNULL(3);

#define TIMETZ_GT(t1,t2) \
    DatumGetBool(DirectFunctionCall2(timetz_gt,t1,t2))
#define TIMETZ_LT(t1,t2) \
    DatumGetBool(DirectFunctionCall2(timetz_lt,t1,t2))

    /*
     * If both endpoints of interval 1 are null, the result is null (unknown).
     * If just one endpoint is null, take ts1 as the non-null one. Otherwise,
     * take ts1 as the lesser endpoint.
     */
    if (ts1IsNull)
    {
        if (te1IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts1 = te1;
        te1IsNull = true;
    }
    else if (!te1IsNull)
    {
        if (TIMETZ_GT(ts1, te1))
        {
            Datum       tt = ts1;

            ts1 = te1;
            te1 = tt;
        }
    }

    /* Likewise for interval 2. */
    if (ts2IsNull)
    {
        if (te2IsNull)
            PG_RETURN_NULL();
        /* swap null for non-null */
        ts2 = te2;
        te2IsNull = true;
    }
    else if (!te2IsNull)
    {
        if (TIMETZ_GT(ts2, te2))
        {
            Datum       tt = ts2;

            ts2 = te2;
            te2 = tt;
        }
    }

    /*
     * At this point neither ts1 nor ts2 is null, so we can consider three
     * cases: ts1 > ts2, ts1 < ts2, ts1 = ts2
     */
    if (TIMETZ_GT(ts1, ts2))
    {
        /*
         * This case is ts1 < te2 OR te1 < te2, which may look redundant but
         * in the presence of nulls it's not quite completely so.
         */
        if (te2IsNull)
            PG_RETURN_NULL();
        if (TIMETZ_LT(ts1, te2))
            PG_RETURN_BOOL(true);
        if (te1IsNull)
            PG_RETURN_NULL();

        /*
         * If te1 is not null then we had ts1 <= te1 above, and we just found
         * ts1 >= te2, hence te1 >= te2.
         */
        PG_RETURN_BOOL(false);
    }
    else if (TIMETZ_LT(ts1, ts2))
    {
        /* This case is ts2 < te1 OR te2 < te1 */
        if (te1IsNull)
            PG_RETURN_NULL();
        if (TIMETZ_LT(ts2, te1))
            PG_RETURN_BOOL(true);
        if (te2IsNull)
            PG_RETURN_NULL();

        /*
         * If te2 is not null then we had ts2 <= te2 above, and we just found
         * ts2 >= te1, hence te2 >= te1.
         */
        PG_RETURN_BOOL(false);
    }
    else
    {
        /*
         * For ts1 = ts2 the spec says te1 <> te2 OR te1 = te2, which is a
         * rather silly way of saying "true if both are nonnull, else null".
         */
        if (te1IsNull || te2IsNull)
            PG_RETURN_NULL();
        PG_RETURN_BOOL(true);
    }

#undef TIMETZ_GT
#undef TIMETZ_LT
}


Datum
timetz_time(PG_FUNCTION_ARGS)
{
    TimeTzADT  *timetz = PG_GETARG_TIMETZADT_P(0);
    TimeADT     result;

    /* swallow the time zone and just return the time */
    result = timetz->time;

    PG_RETURN_TIMEADT(result);
}


Datum
time_timetz(PG_FUNCTION_ARGS)
{
    TimeADT     time = PG_GETARG_TIMEADT(0);
    TimeTzADT  *result;
    struct pg_tm tt,
               *tm = &tt;
    fsec_t      fsec;
    int         tz;

    GetCurrentDateTime(tm);
    time2tm(time, tm, &fsec);
    tz = DetermineTimeZoneOffset(tm, session_timezone);

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    result->time = time;
    result->zone = tz;

    PG_RETURN_TIMETZADT_P(result);
}


/* timestamptz_timetz()
 * Convert timestamp to timetz data type.
 */
Datum
timestamptz_timetz(PG_FUNCTION_ARGS)
{
    TimestampTz timestamp = PG_GETARG_TIMESTAMP(0);
    TimeTzADT  *result;
    struct pg_tm tt,
               *tm = &tt;
    int         tz;
    fsec_t      fsec;

    if (TIMESTAMP_NOT_FINITE(timestamp))
        PG_RETURN_NULL();

    if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("timestamp out of range")));

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    tm2timetz(tm, fsec, tz, result);

    PG_RETURN_TIMETZADT_P(result);
}


/* datetimetz_timestamptz()
 * Convert date and timetz to timestamp with time zone data type.
 * Timestamp is stored in GMT, so add the time zone
 * stored with the timetz to the result.
 * - thomas 2000-03-10
 */
Datum
datetimetz_timestamptz(PG_FUNCTION_ARGS)
{
    DateADT     date = PG_GETARG_DATEADT(0);
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
    TimestampTz result;

    if (DATE_IS_NOBEGIN(date))
        TIMESTAMP_NOBEGIN(result);
    else if (DATE_IS_NOEND(date))
        TIMESTAMP_NOEND(result);
    else
    {
        /*
         * Date's range is wider than timestamp's, so check for boundaries.
         * Since dates have the same minimum values as timestamps, only upper
         * boundary need be checked for overflow.
         */
        if (date >= (TIMESTAMP_END_JULIAN - POSTGRES_EPOCH_JDATE))
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("date out of range for timestamp")));
        result = date * USECS_PER_DAY + time->time + time->zone * USECS_PER_SEC;

        /*
         * Since it is possible to go beyond allowed timestamptz range because
         * of time zone, check for allowed timestamp range after adding tz.
         */
        if (!IS_VALID_TIMESTAMP(result))
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                     errmsg("date out of range for timestamp")));
    }

    PG_RETURN_TIMESTAMP(result);
}


/* timetz_part()
 * Extract specified field from time type.
 */
Datum
timetz_part(PG_FUNCTION_ARGS)
{
    text       *units = PG_GETARG_TEXT_PP(0);
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
    float8      result;
    int         type,
                val;
    char       *lowunits;

    lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
                                            VARSIZE_ANY_EXHDR(units),
                                            false);

    type = DecodeUnits(0, lowunits, &val);
    if (type == UNKNOWN_FIELD)
        type = DecodeSpecial(0, lowunits, &val);

    if (type == UNITS)
    {
        double      dummy;
        int         tz;
        fsec_t      fsec;
        struct pg_tm tt,
                   *tm = &tt;

        timetz2tm(time, tm, &fsec, &tz);

        switch (val)
        {
            case DTK_TZ:
                result = -tz;
                break;

            case DTK_TZ_MINUTE:
                result = -tz;
                result /= SECS_PER_MINUTE;
                FMODULO(result, dummy, (double) SECS_PER_MINUTE);
                break;

            case DTK_TZ_HOUR:
                dummy = -tz;
                FMODULO(dummy, result, (double) SECS_PER_HOUR);
                break;

            case DTK_MICROSEC:
                result = tm->tm_sec * 1000000.0 + fsec;
                break;

            case DTK_MILLISEC:
                result = tm->tm_sec * 1000.0 + fsec / 1000.0;
                break;

            case DTK_SECOND:
                result = tm->tm_sec + fsec / 1000000.0;
                break;

            case DTK_MINUTE:
                result = tm->tm_min;
                break;

            case DTK_HOUR:
                result = tm->tm_hour;
                break;

            case DTK_DAY:
            case DTK_MONTH:
            case DTK_QUARTER:
            case DTK_YEAR:
            case DTK_DECADE:
            case DTK_CENTURY:
            case DTK_MILLENNIUM:
            default:
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                         errmsg("\"time with time zone\" units \"%s\" not recognized",
                                lowunits)));
                result = 0;
        }
    }
    else if (type == RESERV && val == DTK_EPOCH)
    {
        result = time->time / 1000000.0 + time->zone;
    }
    else
    {
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("\"time with time zone\" units \"%s\" not recognized",
                        lowunits)));
        result = 0;
    }

    PG_RETURN_FLOAT8(result);
}

/* timetz_zone()
 * Encode time with time zone type with specified time zone.
 * Applies DST rules as of the current date.
 */
Datum
timetz_zone(PG_FUNCTION_ARGS)
{
    text       *zone = PG_GETARG_TEXT_PP(0);
    TimeTzADT  *t = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;
    int         tz;
    char        tzname[TZ_STRLEN_MAX + 1];
    char       *lowzone;
    int         type,
                val;
    pg_tz      *tzp;

    /*
     * Look up the requested timezone.  First we look in the timezone
     * abbreviation table (to handle cases like "EST"), and if that fails, we
     * look in the timezone database (to handle cases like
     * "America/New_York").  (This matches the order in which timestamp input
     * checks the cases; it's important because the timezone database unwisely
     * uses a few zone names that are identical to offset abbreviations.)
     */
    text_to_cstring_buffer(zone, tzname, sizeof(tzname));

    /* DecodeTimezoneAbbrev requires lowercase input */
    lowzone = downcase_truncate_identifier(tzname,
                                           strlen(tzname),
                                           false);

    type = DecodeTimezoneAbbrev(0, lowzone, &val, &tzp);

    if (type == TZ || type == DTZ)
    {
        /* fixed-offset abbreviation */
        tz = -val;
    }
    else if (type == DYNTZ)
    {
        /* dynamic-offset abbreviation, resolve using current time */
        pg_time_t   now = (pg_time_t) time(NULL);
        struct pg_tm *tm;

        tm = pg_localtime(&now, tzp);
        tz = DetermineTimeZoneAbbrevOffset(tm, tzname, tzp);
    }
    else
    {
        /* try it as a full zone name */
        tzp = pg_tzset(tzname);
        if (tzp)
        {
            /* Get the offset-from-GMT that is valid today for the zone */
            pg_time_t   now = (pg_time_t) time(NULL);
            struct pg_tm *tm;

            tm = pg_localtime(&now, tzp);
            tz = -tm->tm_gmtoff;
        }
        else
        {
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("time zone \"%s\" not recognized", tzname)));
            tz = 0;             /* keep compiler quiet */
        }
    }

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    result->time = t->time + (t->zone - tz) * USECS_PER_SEC;
    while (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;
    while (result->time >= USECS_PER_DAY)
        result->time -= USECS_PER_DAY;

    result->zone = tz;

    PG_RETURN_TIMETZADT_P(result);
}

/* timetz_izone()
 * Encode time with time zone type with specified time interval as time zone.
 */
Datum
timetz_izone(PG_FUNCTION_ARGS)
{
    Interval   *zone = PG_GETARG_INTERVAL_P(0);
    TimeTzADT  *time = PG_GETARG_TIMETZADT_P(1);
    TimeTzADT  *result;
    int         tz;

    if (zone->month != 0 || zone->day != 0)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("interval time zone \"%s\" must not include months or days",
                        DatumGetCString(DirectFunctionCall1(interval_out,
                                                            PointerGetDatum(zone))))));

    tz = -(zone->time / USECS_PER_SEC);

    result = (TimeTzADT *) palloc(sizeof(TimeTzADT));

    result->time = time->time + (time->zone - tz) * USECS_PER_SEC;
    while (result->time < INT64CONST(0))
        result->time += USECS_PER_DAY;
    while (result->time >= USECS_PER_DAY)
        result->time -= USECS_PER_DAY;

    result->zone = tz;

    PG_RETURN_TIMETZADT_P(result);
}