diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 59db3b180c..4f5f5d6b7e 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.264 2001/10/18 23:16:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.265 2001/10/20 01:02:14 thomas Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -887,13 +887,18 @@ zone_value:  Sconst
 		| ConstInterval Sconst opt_interval
 			{
 				A_Const *n = (A_Const *) makeStringConst($2, $1);
-				n->typename->typmod = (($3 << 16) | 0xFFFF);
+				if ($3 != -1)
+					n->typename->typmod = (($3 << 16) | 0xFFFF);
 				$$ = (Node *)n;
 			}
 		| ConstInterval '(' Iconst ')' Sconst opt_interval
 			{
 				A_Const *n = (A_Const *) makeStringConst($5, $1);
-				n->typename->typmod = (($3 << 16) | $6);
+				if ($6 != -1)
+					n->typename->typmod = (($6 << 16) | $3);
+				else
+					n->typename->typmod = ((0x7FFF << 16) | $3);
+
 				$$ = (Node *)n;
 			}
 		| FCONST
@@ -4044,12 +4049,13 @@ SimpleTypename:  ConstTypename
 		| ConstInterval opt_interval
 				{
 					$$ = $1;
-					$$->typmod = (($2 << 16) | 0xFFFF);
+					if ($2 != -1)
+						$$->typmod = ((($2 & 0x7FFF) << 16) | 0xFFFF);
 				}
 		| ConstInterval '(' Iconst ')' opt_interval
 				{
 					$$ = $1;
-					$$->typmod = (($5 << 16) | $3);
+					$$->typmod = ((($5 & 0x7FFF) << 16) | $3);
 				}
 		;
 
@@ -5625,7 +5631,9 @@ AexprConst:  Iconst
 					n->typename = $1;
 					n->val.type = T_String;
 					n->val.val.str = $2;
-					n->typename->typmod = (($3 << 16) | 0xFFFF);
+					/* precision is not specified, but fields may be... */
+					if ($3 != -1)
+						n->typename->typmod = ((($3 & 0x7FFF) << 16) | 0xFFFF);
 					$$ = (Node *)n;
 				}
 		| ConstInterval '(' Iconst ')' Sconst opt_interval
@@ -5634,7 +5642,9 @@ AexprConst:  Iconst
 					n->typename = $1;
 					n->val.type = T_String;
 					n->val.val.str = $5;
-					n->typename->typmod = (($6 << 16) | $3);
+					/* precision specified, and fields may be... */
+					n->typename->typmod = ((($6 & 0x7FFF) << 16) | $3);
+
 					$$ = (Node *)n;
 				}
 		| ParamNo
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 275231983e..6d6fbd6b45 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/datetime.c,v 1.73 2001/10/18 17:30:15 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/datetime.c,v 1.74 2001/10/20 01:02:18 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -385,17 +385,22 @@ j2day(int date)
 }	/* j2day() */
 
 
+/* TrimTrailingZeros()
+ * ... resulting from printing numbers with full precision.
+ */
 void
 TrimTrailingZeros(char *str)
 {
 	int len = strlen(str);
 
+#if 0
 	/* chop off trailing one to cope with interval rounding */
 	if (strcmp((str + len - 4), "0001") == 0)
 	{
 		len -= 4;
 		*(str + len) = '\0';
 	}
+#endif
 
 	/* chop off trailing zeros... */
 	while ((*(str + len - 1) == '0')
@@ -905,11 +910,12 @@ DecodeDateTime(char **field, int *ftype, int nf,
 						break;
 
 					case UNITS:
-						ptype = val;
 						tmask = 0;
+						ptype = val;
 						break;
 
 					case DTK_ISO_TIME:
+						tmask = 0;
 						if ((i < 1) || (i >= (nf-1))
 							|| (ftype[i-1] != DTK_DATE)
 							|| (ftype[i+1] != DTK_TIME))
@@ -2267,10 +2273,10 @@ EncodeDateTime(struct tm * tm, double fsec, int *tzp, char **tzn, int style, cha
 				}
 
 				/* tzp == NULL indicates that we don't want *any* time zone info in the output string.
-				 * *tzn != NULL indicates that we *have* time zone info available.
+				 * *tzn != NULL indicates that we have alpha time zone info available.
 				 * tm_isdst != -1 indicates that we have a valid time zone translation.
 				 */
-				if ((tzp != NULL) && (*tzn != NULL) && (tm->tm_isdst >= 0))
+				if ((tzp != NULL) && (tm->tm_isdst >= 0))
 				{
 					hour = -(*tzp / 3600);
 					min = ((abs(*tzp) / 60) % 60);
@@ -2315,14 +2321,18 @@ EncodeDateTime(struct tm * tm, double fsec, int *tzp, char **tzn, int style, cha
 					sprintf((str + strlen(str)), ":%02.0f", sec);
 				}
 
-				if ((*tzn != NULL) && (tm->tm_isdst >= 0))
-					sprintf((str + strlen(str)), " %.*s", MAXTZLEN, *tzn);
-
-				else if (tzp != NULL)
+				if ((tzp != NULL) && (tm->tm_isdst >= 0))
 				{
-					hour = -(*tzp / 3600);
-					min = ((abs(*tzp) / 60) % 60);
-					sprintf((str + strlen(str)), ((min != 0) ? "%+03d:%02d" : "%+03d"), hour, min);
+					if (*tzn != NULL)
+					{
+						sprintf((str + strlen(str)), " %.*s", MAXTZLEN, *tzn);
+					}
+					else
+					{
+						hour = -(*tzp / 3600);
+						min = ((abs(*tzp) / 60) % 60);
+						sprintf((str + strlen(str)), ((min != 0) ? "%+03d:%02d" : "%+03d"), hour, min);
+					}
 				}
 			}
 			else
@@ -2353,14 +2363,18 @@ EncodeDateTime(struct tm * tm, double fsec, int *tzp, char **tzn, int style, cha
 					sprintf((str + strlen(str)), ":%02.0f", sec);
 				}
 
-				if ((*tzn != NULL) && (tm->tm_isdst >= 0))
-					sprintf((str + strlen(str)), " %.*s", MAXTZLEN, *tzn);
-
-				else if (tzp != NULL)
+				if ((tzp != NULL) && (tm->tm_isdst >= 0))
 				{
-					hour = -(*tzp / 3600);
-					min = ((abs(*tzp) / 60) % 60);
-					sprintf((str + strlen(str)), ((min != 0) ? "%+03d:%02d" : "%+03d"), hour, min);
+					if (*tzn != NULL)
+					{
+						sprintf((str + strlen(str)), " %.*s", MAXTZLEN, *tzn);
+					}
+					else
+					{
+						hour = -(*tzp / 3600);
+						min = ((abs(*tzp) / 60) % 60);
+						sprintf((str + strlen(str)), ((min != 0) ? "%+03d:%02d" : "%+03d"), hour, min);
+					}
 				}
 			}
 			else
@@ -2403,14 +2417,23 @@ EncodeDateTime(struct tm * tm, double fsec, int *tzp, char **tzn, int style, cha
 
 				sprintf((str + strlen(str)), " %04d", tm->tm_year);
 
-				if ((tzp != NULL) && (*tzn != NULL) && (tm->tm_isdst >= 0))
-					sprintf((str + strlen(str)), " %.*s", MAXTZLEN, *tzn);
-
-				else if (HasCTZSet && (tzp != NULL))
+				if ((tzp != NULL) && (tm->tm_isdst >= 0))
 				{
-					hour = -(*tzp / 3600);
-					min = ((abs(*tzp) / 60) % 60);
-					sprintf((str + strlen(str)), ((min != 0) ? "%+03d:%02d" : "%+03d"), hour, min);
+					if (*tzn != NULL)
+					{
+						sprintf((str + strlen(str)), " %.*s", MAXTZLEN, *tzn);
+					}
+					else
+					{
+						/* We have a time zone, but no string version.
+						 * Use the numeric form, but be sure to include a leading space
+						 * to avoid formatting something which would be rejected by the
+						 * date/time parser later. - thomas 2001-10-19
+						 */
+						hour = -(*tzp / 3600);
+						min = ((abs(*tzp) / 60) % 60);
+						sprintf((str + strlen(str)), ((min != 0) ? " %+03d:%02d" : " %+03d"), hour, min);
+					}
 				}
 			}
 			else
diff --git a/src/backend/utils/adt/nabstime.c b/src/backend/utils/adt/nabstime.c
index 55642a1c09..29608aa78d 100644
--- a/src/backend/utils/adt/nabstime.c
+++ b/src/backend/utils/adt/nabstime.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/nabstime.c,v 1.89 2001/10/18 19:52:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/nabstime.c,v 1.90 2001/10/20 01:02:18 thomas Exp $
  *
  * NOTES
  *
@@ -256,7 +256,7 @@ GetCurrentAbsoluteTimeUsec(int *usec)
 	};
 
 	return (AbsoluteTime) now;
-}	/* GetCurrentAbsoluteTime() */
+}	/* GetCurrentAbsoluteTimeUsec() */
 
 
 void
@@ -344,7 +344,7 @@ abstime2tm(AbsoluteTime _time, int *tzp, struct tm * tm, char **tzn)
 		{
 			*tzp = CTimeZone;
 			tm->tm_gmtoff = CTimeZone;
-			tm->tm_isdst = -1;
+			tm->tm_isdst = 0;
 			tm->tm_zone = NULL;
 			if (tzn != NULL)
 				*tzn = NULL;
@@ -366,6 +366,10 @@ abstime2tm(AbsoluteTime _time, int *tzp, struct tm * tm, char **tzn)
 			}
 		}
 	}
+	else
+	{
+		tm->tm_isdst = -1;
+	}
 #elif defined(HAVE_INT_TIMEZONE)
 	if (tzp != NULL)
 	{
@@ -376,7 +380,7 @@ abstime2tm(AbsoluteTime _time, int *tzp, struct tm * tm, char **tzn)
 		if (HasCTZSet)
 		{
 			*tzp = CTimeZone;
-			tm->tm_isdst = -1;
+			tm->tm_isdst = 0;
 			if (tzn != NULL)
 				*tzn = NULL;
 		}
@@ -397,6 +401,10 @@ abstime2tm(AbsoluteTime _time, int *tzp, struct tm * tm, char **tzn)
 			}
 		}
 	}
+	else
+	{
+		tm->tm_isdst = -1;
+	}
 #endif
 #else							/* not (HAVE_TM_ZONE || HAVE_INT_TIMEZONE) */
 	if (tzp != NULL)
@@ -426,6 +434,10 @@ abstime2tm(AbsoluteTime _time, int *tzp, struct tm * tm, char **tzn)
 			}
 		}
 	}
+	else
+	{
+		tm->tm_isdst = -1;
+	}
 #endif
 
 	return;
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index efe4a50146..f39e85b235 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.57 2001/10/18 19:54:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.58 2001/10/20 01:02:18 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -374,14 +374,14 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod)
 {
 	if (typmod != -1)
 	{
-		int range = ((typmod >> 16) & 0xFFFF);
+		int range = ((typmod >> 16) & 0x7FFF);
 		int precision = (typmod & 0xFFFF);
 
-		if (range == 0xFFFF)
+		if (range == 0x7FFF)
 		{
 			/* Do nothing... */
 		}
-		if (range == MASK(YEAR))
+		else if (range == MASK(YEAR))
 		{
 			interval->month = ((interval->month / 12) * 12);
 			interval->time = 0;
@@ -483,7 +483,18 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod)
 				IntervalScale = pow(10.0, IntervalTypmod);
 			}
 
-			interval->time = (rint(interval->time * IntervalScale) / IntervalScale);
+			/* Hmm. For the time field, we can get to a large value
+			 * since we store everything related to an absolute interval
+			 * (e.g. years worth of days) in this one field. So we have
+			 * precision problems doing rint() on this field if the field
+			 * is too large. This resulted in an annoying "...0001" appended
+			 * to the printed result on my Linux box.
+			 * I hate doing an expensive math operation like log10()
+			 * to avoid this, but what else can we do??
+			 * - thomas 2001-10-19
+			 */
+			if ((log10(interval->time) + IntervalTypmod) <= 13)
+				interval->time = (rint(interval->time * IntervalScale) / IntervalScale);
 		}
 	}
 
@@ -671,14 +682,15 @@ timestamp2tm(Timestamp dt, int *tzp, struct tm * tm, double *fsec, char **tzn)
 		else
 		{
 			*tzp = 0;
-			tm->tm_isdst = 0;
+			/* Mark this as *no* time zone available */
+			tm->tm_isdst = -1;
 			if (tzn != NULL)
 				*tzn = NULL;
 		}
 	}
 	else
 	{
-		tm->tm_isdst = 0;
+		tm->tm_isdst = -1;
 		if (tzn != NULL)
 			*tzn = NULL;
 	}
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index c0dec19390..f911fc368f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -359,7 +359,7 @@ SELECT '' AS "64", d1 + interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
     | Tue Feb 10 17:32:01 1998 PST
     | Tue Feb 10 17:32:01 1998 PST
     | Wed Jun 10 17:32:01 1998 PDT
-    | Sun Sep 22 11:19:20 2002 PDT
+    | Sun Sep 22 18:19:20 2002 PDT
     | Thu Mar 15 08:14:01 2001 PST
     | Thu Mar 15 04:14:02 2001 PST
     | Thu Mar 15 02:14:03 2001 PST
@@ -428,7 +428,7 @@ SELECT '' AS "64", d1 - interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
     | Sat Feb 10 17:32:01 1996 PST
     | Sat Feb 10 17:32:01 1996 PST
     | Mon Jun 10 17:32:01 1996 PDT
-    | Fri Sep 22 11:19:20 2000 PDT
+    | Fri Sep 22 18:19:20 2000 PDT
     | Mon Mar 15 08:14:01 1999 PST
     | Mon Mar 15 04:14:02 1999 PST
     | Mon Mar 15 02:14:03 1999 PST
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index dd7ef75ce8..70325aac85 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -152,7 +152,7 @@ SELECT '' AS "64", d1 FROM TIMESTAMPTZ_TBL;
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Tue Jun 10 17:32:01 1997 PDT
-    | Sat Sep 22 11:19:20 2001 PDT
+    | Sat Sep 22 18:19:20 2001 PDT
     | Wed Mar 15 08:14:01 2000 PST
     | Wed Mar 15 04:14:02 2000 PST
     | Wed Mar 15 02:14:03 2000 PST
@@ -220,7 +220,7 @@ SELECT '' AS "48", d1 FROM TIMESTAMPTZ_TBL
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Tue Jun 10 17:32:01 1997 PDT
-    | Sat Sep 22 11:19:20 2001 PDT
+    | Sat Sep 22 18:19:20 2001 PDT
     | Wed Mar 15 08:14:01 2000 PST
     | Wed Mar 15 04:14:02 2000 PST
     | Wed Mar 15 02:14:03 2000 PST
@@ -304,7 +304,7 @@ SELECT '' AS "63", d1 FROM TIMESTAMPTZ_TBL
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Tue Jun 10 17:32:01 1997 PDT
-    | Sat Sep 22 11:19:20 2001 PDT
+    | Sat Sep 22 18:19:20 2001 PDT
     | Wed Mar 15 08:14:01 2000 PST
     | Wed Mar 15 04:14:02 2000 PST
     | Wed Mar 15 02:14:03 2000 PST
@@ -394,7 +394,7 @@ SELECT '' AS "49", d1 FROM TIMESTAMPTZ_TBL
     | Mon Feb 10 17:32:01 1997 PST
     | Mon Feb 10 17:32:01 1997 PST
     | Tue Jun 10 17:32:01 1997 PDT
-    | Sat Sep 22 11:19:20 2001 PDT
+    | Sat Sep 22 18:19:20 2001 PDT
     | Wed Mar 15 08:14:01 2000 PST
     | Wed Mar 15 04:14:02 2000 PST
     | Wed Mar 15 02:14:03 2000 PST
@@ -449,7 +449,7 @@ SELECT '' AS "54", d1 - timestamp with time zone '1997-01-02' AS diff
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 159 days 16 hours 32 mins 1 sec
-    | @ 1724 days 10 hours 19 mins 20 secs
+    | @ 1724 days 17 hours 19 mins 20 secs
     | @ 1168 days 8 hours 14 mins 1 sec
     | @ 1168 days 4 hours 14 mins 2 secs
     | @ 1168 days 2 hours 14 mins 3 secs
@@ -511,7 +511,7 @@ SELECT '' AS "54", d1 - timestamp with time zone '1997-01-02' AS diff
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 39 days 17 hours 32 mins 1 sec
     | @ 159 days 16 hours 32 mins 1 sec
-    | @ 1724 days 10 hours 19 mins 20 secs
+    | @ 1724 days 17 hours 19 mins 20 secs
     | @ 1168 days 8 hours 14 mins 1 sec
     | @ 1168 days 4 hours 14 mins 2 secs
     | @ 1168 days 2 hours 14 mins 3 secs
@@ -574,7 +574,7 @@ SELECT '' AS "54", d1 as timestamptz,
     | Mon Feb 10 17:32:01 1997 PST    | 1997 |     2 |  10 |   17 |     32 |      1
     | Mon Feb 10 17:32:01 1997 PST    | 1997 |     2 |  10 |   17 |     32 |      1
     | Tue Jun 10 17:32:01 1997 PDT    | 1997 |     6 |  10 |   17 |     32 |      1
-    | Sat Sep 22 11:19:20 2001 PDT    | 2001 |     9 |  22 |   11 |     19 |     20
+    | Sat Sep 22 18:19:20 2001 PDT    | 2001 |     9 |  22 |   18 |     19 |     20
     | Wed Mar 15 08:14:01 2000 PST    | 2000 |     3 |  15 |    8 |     14 |      1
     | Wed Mar 15 04:14:02 2000 PST    | 2000 |     3 |  15 |    4 |     14 |      2
     | Wed Mar 15 02:14:03 2000 PST    | 2000 |     3 |  15 |    2 |     14 |      3
@@ -636,7 +636,7 @@ SELECT '' AS "54", d1 as timestamptz,
     | Mon Feb 10 17:32:01 1997 PST    |       1 |    0 |      0
     | Mon Feb 10 17:32:01 1997 PST    |       1 |    0 |      0
     | Tue Jun 10 17:32:01 1997 PDT    |       2 |    0 |      0
-    | Sat Sep 22 11:19:20 2001 PDT    |       3 |    0 |      0
+    | Sat Sep 22 18:19:20 2001 PDT    |       3 |    0 |      0
     | Wed Mar 15 08:14:01 2000 PST    |       1 |    0 |      0
     | Wed Mar 15 04:14:02 2000 PST    |       1 |    0 |      0
     | Wed Mar 15 02:14:03 2000 PST    |       1 |    0 |      0
@@ -982,7 +982,7 @@ SELECT '' AS to_char_5, to_char(d1, 'HH HH12 HH24 MI SS SSSS')
            | 05 05 17 32 01 63121
            | 05 05 17 32 01 63121
            | 05 05 17 32 01 63121
-           | 11 11 11 19 20 40760
+           | 06 06 18 19 20 65960
            | 08 08 08 14 01 29641
            | 04 04 04 14 02 15242
            | 02 02 02 14 03 8043
@@ -1052,7 +1052,7 @@ SELECT '' AS to_char_6, to_char(d1, '"HH:MI:SS is" HH:MI:SS "\\"text between quo
            | HH:MI:SS is 05:32:01 "text between quote marks"
            | HH:MI:SS is 05:32:01 "text between quote marks"
            | HH:MI:SS is 05:32:01 "text between quote marks"
-           | HH:MI:SS is 11:19:20 "text between quote marks"
+           | HH:MI:SS is 06:19:20 "text between quote marks"
            | HH:MI:SS is 08:14:01 "text between quote marks"
            | HH:MI:SS is 04:14:02 "text between quote marks"
            | HH:MI:SS is 02:14:03 "text between quote marks"
@@ -1123,7 +1123,7 @@ SELECT '' AS to_char_7, to_char(d1, 'HH24--text--MI--text--SS')
            | 17--text--32--text--01
            | 17--text--32--text--01
            | 17--text--32--text--01
-           | 11--text--19--text--20
+           | 18--text--19--text--20
            | 08--text--14--text--01
            | 04--text--14--text--02
            | 02--text--14--text--03
@@ -1264,7 +1264,7 @@ SELECT '' AS to_char_9, to_char(d1, 'YYYY A.D. YYYY a.d. YYYY bc HH:MI:SS P.M. H
            | 1997 A.D. 1997 a.d. 1997 ad 05:32:01 P.M. 05:32:01 p.m. 05:32:01 pm
            | 1997 A.D. 1997 a.d. 1997 ad 05:32:01 P.M. 05:32:01 p.m. 05:32:01 pm
            | 1997 A.D. 1997 a.d. 1997 ad 05:32:01 P.M. 05:32:01 p.m. 05:32:01 pm
-           | 2001 A.D. 2001 a.d. 2001 ad 11:19:20 A.M. 11:19:20 a.m. 11:19:20 am
+           | 2001 A.D. 2001 a.d. 2001 ad 06:19:20 P.M. 06:19:20 p.m. 06:19:20 pm
            | 2000 A.D. 2000 a.d. 2000 ad 08:14:01 A.M. 08:14:01 a.m. 08:14:01 am
            | 2000 A.D. 2000 a.d. 2000 ad 04:14:02 A.M. 04:14:02 a.m. 04:14:02 am
            | 2000 A.D. 2000 a.d. 2000 ad 02:14:03 A.M. 02:14:03 a.m. 02:14:03 am