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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2004-11-01 22:00:30 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2004-11-01 22:00:30 +0000 |
| commit | c4acbb843b0b10204b04be6245db57d50f9cee0e (patch) | |
| tree | f9fa5973c62b9c205b7c798d316acc4712be9453 /src/backend/utils/adt/timestamp.c | |
| parent | 5ba04cd9f17ac91cce7460310a2a6cbd714b7e8a (diff) | |
| download | postgresql-c4acbb843b0b10204b04be6245db57d50f9cee0e.tar.gz postgresql-c4acbb843b0b10204b04be6245db57d50f9cee0e.zip | |
timestamptz_trunc() should only recalculate the timezone when truncating
to DAY precision or coarser; leave the timezone alone when precision is
HOUR or less. This avoids surprises for inputs near a DST transition
time, as per example from Matthew Gabeler-Lee. (The only reason we
recalculate at all is so that outputs that are supposed to represent
days will come out as local midnight, and that's not relevant for sub-day
precision.)
Diffstat (limited to 'src/backend/utils/adt/timestamp.c')
| -rw-r--r-- | src/backend/utils/adt/timestamp.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index 83286502e81..0b7190c3455 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.113 2004/08/30 02:54:39 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.114 2004/11/01 22:00:30 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -2842,6 +2842,7 @@ timestamptz_trunc(PG_FUNCTION_ARGS) int tz; int type, val; + bool redotz = false; char *lowunits; fsec_t fsec; char *tzn; @@ -2872,6 +2873,7 @@ timestamptz_trunc(PG_FUNCTION_ARGS) tm->tm_min = 0; tm->tm_sec = 0; fsec = 0; + redotz = true; break; /* one may consider DTK_THOUSAND and DTK_HUNDRED... */ case DTK_MILLENNIUM: @@ -2885,12 +2887,14 @@ timestamptz_trunc(PG_FUNCTION_ARGS) tm->tm_year = ((tm->tm_year + 999) / 1000) * 1000 - 999; else tm->tm_year = -((999 - (tm->tm_year - 1)) / 1000) * 1000 + 1; + /* FALL THRU */ case DTK_CENTURY: /* truncating to the century? as above: -100, 1, 101... */ if (tm->tm_year > 0) tm->tm_year = ((tm->tm_year + 99) / 100) * 100 - 99; else tm->tm_year = -((99 - (tm->tm_year - 1)) / 100) * 100 + 1; + /* FALL THRU */ case DTK_DECADE: /* @@ -2904,18 +2908,26 @@ timestamptz_trunc(PG_FUNCTION_ARGS) else tm->tm_year = -((8 - (tm->tm_year - 1)) / 10) * 10; } + /* FALL THRU */ case DTK_YEAR: tm->tm_mon = 1; + /* FALL THRU */ case DTK_QUARTER: tm->tm_mon = (3 * ((tm->tm_mon - 1) / 3)) + 1; + /* FALL THRU */ case DTK_MONTH: tm->tm_mday = 1; + /* FALL THRU */ case DTK_DAY: tm->tm_hour = 0; + redotz = true; /* for all cases >= DAY */ + /* FALL THRU */ case DTK_HOUR: tm->tm_min = 0; + /* FALL THRU */ case DTK_MINUTE: tm->tm_sec = 0; + /* FALL THRU */ case DTK_SECOND: fsec = 0; break; @@ -2941,7 +2953,8 @@ timestamptz_trunc(PG_FUNCTION_ARGS) result = 0; } - tz = DetermineLocalTimeZone(tm); + if (redotz) + tz = DetermineLocalTimeZone(tm); if (tm2timestamp(tm, fsec, &tz, &result) != 0) ereport(ERROR, |