Fix AT TIME ZONE for timestamps without time zones:

	test=> select ('2005-07-20 00:00:00'::timestamp without time zone) at
	time zone 'Europe/Paris';
	        timezone
	------------------------
	 2005-07-19 22:00:00-04

Udpate documentation.

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 43f720ae10feac68b276d551a4fae5b0f499d846..59813e16f164c72899631a28c5ad03d7ca7da8db 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
 
 
@@ -5693,7 +5693,7 @@ SELECT date_trunc('year', TIMESTAMP '2001-02-16 20:38:40');
          timestamp without time zone AT TIME ZONE zone
         
         timestamp with time zone
-        Convert local time in given time zone to UTC
+        Treat given timestamp without time zone as located in the specified time zone
        
 
        
@@ -5701,7 +5701,7 @@ SELECT date_trunc('year', TIMESTAMP '2001-02-16 20:38:40');
          timestamp with time zone AT TIME ZONE zone
         
         timestamp without time zone
-        Convert UTC to local time in given time zone
+        Convert given timestamp with time zone to the new time zone
        
 
        
@@ -5709,7 +5709,7 @@ SELECT date_trunc('year', TIMESTAMP '2001-02-16 20:38:40');
          time with time zone AT TIME ZONE zone
         
         time with time zone
-        Convert local time across time zones
+        Convert given time with time zone to the new time zone
        
       
      
@@ -5720,7 +5720,8 @@ SELECT date_trunc('year', TIMESTAMP '2001-02-16 20:38:40');
     specified either as a text string (e.g., 'PST')
     or as an interval (e.g., INTERVAL '-08:00').
     In the text case, the available zone names are those shown in
-    .
+    .  The time zone can
+    also be implied using the default time zone for that session.
    
 
    
@@ -5732,10 +5733,9 @@ SELECT TIMESTAMP '2001-02-16 20:38:40' AT TIME ZONE 'MST';
 SELECT TIMESTAMP WITH TIME ZONE '2001-02-16 20:38:40-05' AT TIME ZONE 'MST';
 Result: 2001-02-16 18:38:40
 
-    The first example takes a zone-less time stamp and interprets it as MST time
-    (UTC-7) to produce a UTC time stamp, which is then rotated to PST (UTC-8)
-    for display.  The second example takes a time stamp specified in EST
-    (UTC-5) and converts it to local time in MST (UTC-7).
+    The first example takes a time stamp without time zone and interprets it as MST time
+    (UTC-7), which is then converted to PST (UTC-8) for display.  The second example takes 
+    a time stamp specified in EST (UTC-5) and converts it to local time in MST (UTC-7).
    
 
    

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 73a68a1a22e21e617b104ba7dd3f8601f2b380bd..2d9b5ad7d0d6ce25b644c2405a105761c9533d53 100644 (file)
--- 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 1.141 2005/07/22 19:00:54 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.142 2005/07/22 21:16:15 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1035,7 +1035,7 @@ timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm, fsec_t *fsec, char **tzn,
 #endif
 
    /* add offset to go from J2000 back to standard Julian date */
-   date      +=POSTGRES_EPOCH_JDATE;
+   date += POSTGRES_EPOCH_JDATE;
 
    /* Julian day routine does not work for negative Julian days */
    if (date <0 || date >(Timestamp) INT_MAX)
@@ -1147,8 +1147,8 @@ tm2timestamp(struct pg_tm *tm, fsec_t fsec, int *tzp, Timestamp *result)
        return -1;
 
    date = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
-
    time = time2t(tm->tm_hour, tm->tm_min, tm->tm_sec, fsec);
+
 #ifdef HAVE_INT64_TIMESTAMP
    *result = date * USECS_PER_DAY + time;
    /* check for major overflow */
@@ -2673,7 +2673,7 @@ timestamp_text(PG_FUNCTION_ARGS)
    result = palloc(len);
 
    VARATT_SIZEP(result) = len;
-   memmove(VARDATA(result), str, (len - VARHDRSZ));
+   memmove(VARDATA(result), str, len - VARHDRSZ);
 
    pfree(str);
 
@@ -2704,7 +2704,7 @@ text_timestamp(PG_FUNCTION_ARGS)
 
    sp = VARDATA(str);
    dp = dstr;
-   for (i = 0; i < (VARSIZE(str) - VARHDRSZ); i++)
+   for (i = 0; i < VARSIZE(str) - VARHDRSZ; i++)
        *dp++ = *sp++;
    *dp = '\0';
 
@@ -2729,12 +2729,12 @@ timestamptz_text(PG_FUNCTION_ARGS)
 
    str = DatumGetCString(DirectFunctionCall1(timestamptz_out, timestamp));
 
-   len = (strlen(str) + VARHDRSZ);
+   len = strlen(str) + VARHDRSZ;
 
    result = palloc(len);
 
    VARATT_SIZEP(result) = len;
-   memmove(VARDATA(result), str, (len - VARHDRSZ));
+   memmove(VARDATA(result), str, len - VARHDRSZ);
 
    pfree(str);
 
@@ -2764,7 +2764,7 @@ text_timestamptz(PG_FUNCTION_ARGS)
 
    sp = VARDATA(str);
    dp = dstr;
-   for (i = 0; i < (VARSIZE(str) - VARHDRSZ); i++)
+   for (i = 0; i < VARSIZE(str) - VARHDRSZ; i++)
        *dp++ = *sp++;
    *dp = '\0';
 
@@ -2789,7 +2789,7 @@ interval_text(PG_FUNCTION_ARGS)
    str = DatumGetCString(DirectFunctionCall1(interval_out,
                                           IntervalPGetDatum(interval)));
 
-   len = (strlen(str) + VARHDRSZ);
+   len = strlen(str) + VARHDRSZ;
 
    result = palloc(len);
 
@@ -3084,7 +3084,7 @@ timestamptz_trunc(PG_FUNCTION_ARGS)
 
            case DTK_MILLISEC:
 #ifdef HAVE_INT64_TIMESTAMP
-               fsec = ((fsec / 1000) * 1000);
+               fsec = (fsec / 1000) * 1000;
 #else
                fsec = rint(fsec * 1000) / 1000;
 #endif
@@ -3181,7 +3181,7 @@ interval_trunc(PG_FUNCTION_ARGS)
 
                case DTK_MILLISEC:
 #ifdef HAVE_INT64_TIMESTAMP
-                   fsec = ((fsec / 1000) * 1000);
+                   fsec = (fsec / 1000) * 1000;
 #else
                    fsec = rint(fsec * 1000) / 1000;
 #endif
@@ -3932,7 +3932,7 @@ timestamp_zone(PG_FUNCTION_ARGS)
 {
    text       *zone = PG_GETARG_TEXT_P(0);
    Timestamp timestamp = PG_GETARG_TIMESTAMP(1);
-   Timestamp result;
+   TimestampTz result;
    int         tz;
    pg_tz      *tzp;
    char        tzname[TZ_STRLEN_MAX+1];
@@ -3968,7 +3968,7 @@ timestamp_zone(PG_FUNCTION_ARGS)
                        tzname)));
        PG_RETURN_NULL();
    }
-   PG_RETURN_TIMESTAMPTZ(timestamp2timestamptz(result));
+   PG_RETURN_TIMESTAMPTZ(result);
 }
 
 /* timestamp_izone()