Rework the date/time parsing to tighten up some cases and to enable other

cases which should have worked but did not.
Now supports julian day (J2452271), ISO time labels (T040506) and various
 combinations of spaces and run-togethers of dates, times, and time zones.
All regression tests pass, and I have more tests to add after the 7.2
 release (don't want to require changes to the ancillary horology result
 files until after then).

src/backend/utils/adt/timestamp.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.60 2001/11/21 18:29:48 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.61 2001/12/29 18:31:31 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2461,6 +2461,11 @@ timestamp_part(PG_FUNCTION_ARGS)
 				result = (tm->tm_year / 1000);
 				break;
 
+			case DTK_JULIAN:
+				result = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday);
+				result += (((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec) / 86400e0);
+				break;
+
 			case DTK_TZ:
 			case DTK_TZ_MINUTE:
 			case DTK_TZ_HOUR:
@@ -2549,7 +2554,8 @@ timestamptz_part(PG_FUNCTION_ARGS)
 		PG_RETURN_FLOAT8(result);
 	}
 
-	if ((type == UNITS) && (timestamp2tm(timestamp, &tz, tm, &fsec, &tzn) == 0))
+	if ((type == UNITS)
+		&& (timestamp2tm(timestamp, &tz, tm, &fsec, &tzn) == 0))
 	{
 		switch (val)
 		{
@@ -2619,6 +2625,11 @@ timestamptz_part(PG_FUNCTION_ARGS)
 				result = (tm->tm_year / 1000);
 				break;
 
+			case DTK_JULIAN:
+				result = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday);
+				result += (((((tm->tm_hour * 60) + tm->tm_min) * 60) + tm->tm_sec) / 86400e0);
+				break;
+
 			default:
 				elog(ERROR, "TIMESTAMP WITH TIME ZONE units '%s' not supported", lowunits);
 				result = 0;

src/include/utils/datetime.h

@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: datetime.h,v 1.26 2001/11/05 17:46:36 momjian Exp $
+ * $Id: datetime.h,v 1.27 2001/12/29 18:31:48 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -108,6 +108,9 @@
 #define AGO		17
 #define ABS_BEFORE		18
 #define ABS_AFTER		19
+/* generic fields to help with parsing */
+#define DATE	20
+#define TIME	21
 /* reserved for unrecognized string values */
 #define UNKNOWN_FIELD	31
 
@@ -163,9 +166,6 @@
 #define DTK_TZ_HOUR		34
 #define DTK_TZ_MINUTE	35
 
-#define DTK_ISO_DATE	36
-#define DTK_ISO_TIME	37
-
 
 /*
  * Bit mask definitions for time parsing.