Support timezone abbreviations that sometimes change.

Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time.  But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation.  Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.

To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone.  For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time.  However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.

The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970.  The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.

While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.

This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib.  Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.

This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time.  We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.

In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.

2 files changed, 263 insertions, 277 deletions

diff --git a/src/interfaces/ecpg/pgtypeslib/dt.h b/src/interfaces/ecpg/pgtypeslib/dt.h
index c2635c7b287..145e2b7c4fb 100644
--- a/src/interfaces/ecpg/pgtypeslib/dt.h
+++ b/src/interfaces/ecpg/pgtypeslib/dt.h
@@ -42,6 +42,7 @@ typedef double fsec_t;
 
 
 #define DAGO			"ago"
+#define DCURRENT		"current"
 #define EPOCH			"epoch"
 #define INVALID			"invalid"
 #define EARLY			"-infinity"
@@ -68,7 +69,6 @@ typedef double fsec_t;
 #define DA_D			"ad"
 #define DB_C			"bc"
 #define DTIMEZONE		"timezone"
-#define DCURRENT		   "current"
 
 /*
  * Fundamental time field definitions for parsing.
@@ -85,7 +85,7 @@ typedef double fsec_t;
 #define BC		1
 
 /*
- * Fields for time decoding.
+ * Field types for time decoding.
  *
  * Can't have more of these than there are bits in an unsigned int
  * since these are turned into bit masks during parsing and decoding.
@@ -103,9 +103,9 @@ typedef double fsec_t;
 #define YEAR	2
 #define DAY		3
 #define JULIAN	4
-#define TZ		5
-#define DTZ		6
-#define DTZMOD	7
+#define TZ		5				/* fixed-offset timezone abbreviation */
+#define DTZ		6				/* fixed-offset timezone abbrev, DST */
+#define DYNTZ	7				/* dynamic timezone abbr (unimplemented) */
 #define IGNORE_DTF	8
 #define AMPM	9
 #define HOUR	10
@@ -124,19 +124,25 @@ typedef double fsec_t;
 /* generic fields to help with parsing */
 #define ISODATE 22
 #define ISOTIME 23
+/* hack for parsing two-word timezone specs "MET DST" etc */
+#define DTZMOD	28				/* "DST" as a separate word */
 /* reserved for unrecognized string values */
 #define UNKNOWN_FIELD	31
 
 
 /*
  * Token field definitions for time parsing and decoding.
- * These need to fit into the datetkn table type.
- * At the moment, that means keep them within [-127,127].
- * These are also used for bit masks in DecodeDateDelta()
+ *
+ * Some field type codes (see above) use these as the "value" in datetktbl[].
+ * These are also used for bit masks in DecodeDateTime and friends
  *	so actually restrict them to within [0,31] for now.
  * - thomas 97/06/19
- * Not all of these fields are used for masks in DecodeDateDelta
+ * Not all of these fields are used for masks in DecodeDateTime
  *	so allow some larger than 31. - thomas 1997-11-17
+ *
+ * Caution: there are undocumented assumptions in the code that most of these
+ * values are not equal to IGNORE_DTF nor RESERV.  Be very careful when
+ * renumbering values in either of these apparently-independent lists :-(
  */
 
 #define DTK_NUMBER		0
@@ -207,13 +213,9 @@ typedef double fsec_t;
 /* keep this struct small; it gets used a lot */
 typedef struct
 {
-#if defined(_AIX)
-	char	   *token;
-#else
-	char		token[TOKMAXLEN];
-#endif   /* _AIX */
-	char		type;
-	char		value;			/* this may be unsigned, alas */
+	char		token[TOKMAXLEN + 1];	/* always NUL-terminated */
+	char		type;			/* see field type codes above */
+	int32		value;			/* meaning depends on type */
 } datetkn;
 
 
diff --git a/src/interfaces/ecpg/pgtypeslib/dt_common.c b/src/interfaces/ecpg/pgtypeslib/dt_common.c
index 2286acd428f..7fdd09b3068 100644
--- a/src/interfaces/ecpg/pgtypeslib/dt_common.c
+++ b/src/interfaces/ecpg/pgtypeslib/dt_common.c
@@ -16,38 +16,31 @@ int			day_tab[2][13] = {
 
 typedef long AbsoluteTime;
 
-#define ABS_SIGNBIT				((char) 0200)
-#define POS(n)					(n)
-#define NEG(n)					((n)|ABS_SIGNBIT)
-#define FROMVAL(tp)				(-SIGNEDCHAR((tp)->value) * 15) /* uncompress */
-#define VALMASK					((char) 0177)
-#define SIGNEDCHAR(c)	((c)&ABS_SIGNBIT? -((c)&VALMASK): (c))
-
 static datetkn datetktbl[] = {
 /*	text, token, lexval */
 	{EARLY, RESERV, DTK_EARLY}, /* "-infinity" reserved for "early time" */
-	{"acsst", DTZ, POS(42)},	/* Cent. Australia */
-	{"acst", DTZ, NEG(16)},		/* Atlantic/Porto Acre */
-	{"act", TZ, NEG(20)},		/* Atlantic/Porto Acre */
+	{"acsst", DTZ, 37800},		/* Cent. Australia */
+	{"acst", DTZ, -14400},		/* Atlantic/Porto Acre */
+	{"act", TZ, -18000},		/* Atlantic/Porto Acre */
 	{DA_D, ADBC, AD},			/* "ad" for years >= 0 */
-	{"adt", DTZ, NEG(12)},		/* Atlantic Daylight Time */
-	{"aesst", DTZ, POS(44)},	/* E. Australia */
-	{"aest", TZ, POS(40)},		/* Australia Eastern Std Time */
-	{"aft", TZ, POS(18)},		/* Kabul */
-	{"ahst", TZ, NEG(40)},		/* Alaska-Hawaii Std Time */
-	{"akdt", DTZ, NEG(32)},		/* Alaska Daylight Time */
-	{"akst", DTZ, NEG(36)},		/* Alaska Standard Time */
+	{"adt", DTZ, -10800},		/* Atlantic Daylight Time */
+	{"aesst", DTZ, 39600},		/* E. Australia */
+	{"aest", TZ, 36000},		/* Australia Eastern Std Time */
+	{"aft", TZ, 16200},			/* Kabul */
+	{"ahst", TZ, -36000},		/* Alaska-Hawaii Std Time */
+	{"akdt", DTZ, -28800},		/* Alaska Daylight Time */
+	{"akst", DTZ, -32400},		/* Alaska Standard Time */
 	{"allballs", RESERV, DTK_ZULU},		/* 00:00:00 */
-	{"almst", TZ, POS(28)},		/* Almaty Savings Time */
-	{"almt", TZ, POS(24)},		/* Almaty Time */
+	{"almst", TZ, 25200},		/* Almaty Savings Time */
+	{"almt", TZ, 21600},		/* Almaty Time */
 	{"am", AMPM, AM},
-	{"amst", DTZ, POS(20)},		/* Armenia Summer Time (Yerevan) */
+	{"amst", DTZ, 18000},		/* Armenia Summer Time (Yerevan) */
 #if 0
-	{"amst", DTZ, NEG(12)},		/* Porto Velho */
+	{"amst", DTZ, -10800},		/* Porto Velho */
 #endif
-	{"amt", TZ, POS(16)},		/* Armenia Time (Yerevan) */
-	{"anast", DTZ, POS(52)},	/* Anadyr Summer Time (Russia) */
-	{"anat", TZ, POS(48)},		/* Anadyr Time (Russia) */
+	{"amt", TZ, 14400},			/* Armenia Time (Yerevan) */
+	{"anast", DTZ, 46800},		/* Anadyr Summer Time (Russia) */
+	{"anat", TZ, 43200},		/* Anadyr Time (Russia) */
 	{"apr", MONTH, 4},
 	{"april", MONTH, 4},
 #if 0
@@ -55,376 +48,376 @@ static datetkn datetktbl[] = {
 	aqtt
 	arst
 #endif
-	{"art", TZ, NEG(12)},		/* Argentina Time */
+	{"art", TZ, -10800},		/* Argentina Time */
 #if 0
 	ashst
 	ast							/* Atlantic Standard Time, Arabia Standard
 								 * Time, Acre Standard Time */
 #endif
-	{"ast", TZ, NEG(16)},		/* Atlantic Std Time (Canada) */
+	{"ast", TZ, -14400},		/* Atlantic Std Time (Canada) */
 	{"at", IGNORE_DTF, 0},		/* "at" (throwaway) */
 	{"aug", MONTH, 8},
 	{"august", MONTH, 8},
-	{"awsst", DTZ, POS(36)},	/* W. Australia */
-	{"awst", TZ, POS(32)},		/* W. Australia */
-	{"awt", DTZ, NEG(12)},
-	{"azost", DTZ, POS(0)},		/* Azores Summer Time */
-	{"azot", TZ, NEG(4)},		/* Azores Time */
-	{"azst", DTZ, POS(20)},		/* Azerbaijan Summer Time */
-	{"azt", TZ, POS(16)},		/* Azerbaijan Time */
+	{"awsst", DTZ, 32400},		/* W. Australia */
+	{"awst", TZ, 28800},		/* W. Australia */
+	{"awt", DTZ, -10800},
+	{"azost", DTZ, 0},			/* Azores Summer Time */
+	{"azot", TZ, -3600},		/* Azores Time */
+	{"azst", DTZ, 18000},		/* Azerbaijan Summer Time */
+	{"azt", TZ, 14400},			/* Azerbaijan Time */
 	{DB_C, ADBC, BC},			/* "bc" for years < 0 */
-	{"bdst", TZ, POS(8)},		/* British Double Summer Time */
-	{"bdt", TZ, POS(24)},		/* Dacca */
-	{"bnt", TZ, POS(32)},		/* Brunei Darussalam Time */
-	{"bort", TZ, POS(32)},		/* Borneo Time (Indonesia) */
+	{"bdst", TZ, 7200},			/* British Double Summer Time */
+	{"bdt", TZ, 21600},			/* Dacca */
+	{"bnt", TZ, 28800},			/* Brunei Darussalam Time */
+	{"bort", TZ, 28800},		/* Borneo Time (Indonesia) */
 #if 0
 	bortst
 	bost
 #endif
-	{"bot", TZ, NEG(16)},		/* Bolivia Time */
-	{"bra", TZ, NEG(12)},		/* Brazil Time */
+	{"bot", TZ, -14400},		/* Bolivia Time */
+	{"bra", TZ, -10800},		/* Brazil Time */
 #if 0
 	brst
 	brt
 #endif
-	{"bst", DTZ, POS(4)},		/* British Summer Time */
+	{"bst", DTZ, 3600},			/* British Summer Time */
 #if 0
-	{"bst", TZ, NEG(12)},		/* Brazil Standard Time */
-	{"bst", DTZ, NEG(44)},		/* Bering Summer Time */
+	{"bst", TZ, -10800},		/* Brazil Standard Time */
+	{"bst", DTZ, -39600},		/* Bering Summer Time */
 #endif
-	{"bt", TZ, POS(12)},		/* Baghdad Time */
-	{"btt", TZ, POS(24)},		/* Bhutan Time */
-	{"cadt", DTZ, POS(42)},		/* Central Australian DST */
-	{"cast", TZ, POS(38)},		/* Central Australian ST */
-	{"cat", TZ, NEG(40)},		/* Central Alaska Time */
-	{"cct", TZ, POS(32)},		/* China Coast Time */
+	{"bt", TZ, 10800},			/* Baghdad Time */
+	{"btt", TZ, 21600},			/* Bhutan Time */
+	{"cadt", DTZ, 37800},		/* Central Australian DST */
+	{"cast", TZ, 34200},		/* Central Australian ST */
+	{"cat", TZ, -36000},		/* Central Alaska Time */
+	{"cct", TZ, 28800},			/* China Coast Time */
 #if 0
-	{"cct", TZ, POS(26)},		/* Indian Cocos (Island) Time */
+	{"cct", TZ, 23400},			/* Indian Cocos (Island) Time */
 #endif
-	{"cdt", DTZ, NEG(20)},		/* Central Daylight Time */
-	{"cest", DTZ, POS(8)},		/* Central European Dayl.Time */
-	{"cet", TZ, POS(4)},		/* Central European Time */
-	{"cetdst", DTZ, POS(8)},	/* Central European Dayl.Time */
-	{"chadt", DTZ, POS(55)},	/* Chatham Island Daylight Time (13:45) */
-	{"chast", TZ, POS(51)},		/* Chatham Island Time (12:45) */
+	{"cdt", DTZ, -18000},		/* Central Daylight Time */
+	{"cest", DTZ, 7200},		/* Central European Dayl.Time */
+	{"cet", TZ, 3600},			/* Central European Time */
+	{"cetdst", DTZ, 7200},		/* Central European Dayl.Time */
+	{"chadt", DTZ, 49500},		/* Chatham Island Daylight Time (13:45) */
+	{"chast", TZ, 45900},		/* Chatham Island Time (12:45) */
 #if 0
 	ckhst
 #endif
-	{"ckt", TZ, POS(48)},		/* Cook Islands Time */
-	{"clst", DTZ, NEG(12)},		/* Chile Summer Time */
-	{"clt", TZ, NEG(16)},		/* Chile Time */
+	{"ckt", TZ, 43200},			/* Cook Islands Time */
+	{"clst", DTZ, -10800},		/* Chile Summer Time */
+	{"clt", TZ, -14400},		/* Chile Time */
 #if 0
 	cost
 #endif
-	{"cot", TZ, NEG(20)},		/* Columbia Time */
-	{"cst", TZ, NEG(24)},		/* Central Standard Time */
+	{"cot", TZ, -18000},		/* Columbia Time */
+	{"cst", TZ, -21600},		/* Central Standard Time */
 	{DCURRENT, RESERV, DTK_CURRENT},	/* "current" is always now */
 #if 0
 	cvst
 #endif
-	{"cvt", TZ, POS(28)},		/* Christmas Island Time (Indian Ocean) */
-	{"cxt", TZ, POS(28)},		/* Christmas Island Time (Indian Ocean) */
+	{"cvt", TZ, 25200},			/* Christmas Island Time (Indian Ocean) */
+	{"cxt", TZ, 25200},			/* Christmas Island Time (Indian Ocean) */
 	{"d", UNITS, DTK_DAY},		/* "day of month" for ISO input */
-	{"davt", TZ, POS(28)},		/* Davis Time (Antarctica) */
-	{"ddut", TZ, POS(40)},		/* Dumont-d'Urville Time (Antarctica) */
+	{"davt", TZ, 25200},		/* Davis Time (Antarctica) */
+	{"ddut", TZ, 36000},		/* Dumont-d'Urville Time (Antarctica) */
 	{"dec", MONTH, 12},
 	{"december", MONTH, 12},
-	{"dnt", TZ, POS(4)},		/* Dansk Normal Tid */
+	{"dnt", TZ, 3600},			/* Dansk Normal Tid */
 	{"dow", RESERV, DTK_DOW},	/* day of week */
 	{"doy", RESERV, DTK_DOY},	/* day of year */
-	{"dst", DTZMOD, 6},
+	{"dst", DTZMOD, SECS_PER_HOUR},
 #if 0
-	{"dusst", DTZ, POS(24)},	/* Dushanbe Summer Time */
+	{"dusst", DTZ, 21600},		/* Dushanbe Summer Time */
 #endif
-	{"easst", DTZ, NEG(20)},	/* Easter Island Summer Time */
-	{"east", TZ, NEG(24)},		/* Easter Island Time */
-	{"eat", TZ, POS(12)},		/* East Africa Time */
+	{"easst", DTZ, -18000},		/* Easter Island Summer Time */
+	{"east", TZ, -21600},		/* Easter Island Time */
+	{"eat", TZ, 10800},			/* East Africa Time */
 #if 0
-	{"east", DTZ, POS(16)},		/* Indian Antananarivo Savings Time */
-	{"eat", TZ, POS(12)},		/* Indian Antananarivo Time */
-	{"ect", TZ, NEG(16)},		/* Eastern Caribbean Time */
-	{"ect", TZ, NEG(20)},		/* Ecuador Time */
+	{"east", DTZ, 14400},		/* Indian Antananarivo Savings Time */
+	{"eat", TZ, 10800},			/* Indian Antananarivo Time */
+	{"ect", TZ, -14400},		/* Eastern Caribbean Time */
+	{"ect", TZ, -18000},		/* Ecuador Time */
 #endif
-	{"edt", DTZ, NEG(16)},		/* Eastern Daylight Time */
-	{"eest", DTZ, POS(12)},		/* Eastern Europe Summer Time */
-	{"eet", TZ, POS(8)},		/* East. Europe, USSR Zone 1 */
-	{"eetdst", DTZ, POS(12)},	/* Eastern Europe Daylight Time */
-	{"egst", DTZ, POS(0)},		/* East Greenland Summer Time */
-	{"egt", TZ, NEG(4)},		/* East Greenland Time */
+	{"edt", DTZ, -14400},		/* Eastern Daylight Time */
+	{"eest", DTZ, 10800},		/* Eastern Europe Summer Time */
+	{"eet", TZ, 7200},			/* East. Europe, USSR Zone 1 */
+	{"eetdst", DTZ, 10800},		/* Eastern Europe Daylight Time */
+	{"egst", DTZ, 0},			/* East Greenland Summer Time */
+	{"egt", TZ, -3600},			/* East Greenland Time */
 #if 0
 	ehdt
 #endif
 	{EPOCH, RESERV, DTK_EPOCH}, /* "epoch" reserved for system epoch time */
-	{"est", TZ, NEG(20)},		/* Eastern Standard Time */
+	{"est", TZ, -18000},		/* Eastern Standard Time */
 	{"feb", MONTH, 2},
 	{"february", MONTH, 2},
-	{"fjst", DTZ, NEG(52)},		/* Fiji Summer Time (13 hour offset!) */
-	{"fjt", TZ, NEG(48)},		/* Fiji Time */
-	{"fkst", DTZ, NEG(12)},		/* Falkland Islands Summer Time */
-	{"fkt", TZ, NEG(8)},		/* Falkland Islands Time */
+	{"fjst", DTZ, -46800},		/* Fiji Summer Time (13 hour offset!) */
+	{"fjt", TZ, -43200},		/* Fiji Time */
+	{"fkst", DTZ, -10800},		/* Falkland Islands Summer Time */
+	{"fkt", TZ, -7200},			/* Falkland Islands Time */
 #if 0
 	fnst
 	fnt
 #endif
 	{"fri", DOW, 5},
 	{"friday", DOW, 5},
-	{"fst", TZ, POS(4)},		/* French Summer Time */
-	{"fwt", DTZ, POS(8)},		/* French Winter Time  */
-	{"galt", TZ, NEG(24)},		/* Galapagos Time */
-	{"gamt", TZ, NEG(36)},		/* Gambier Time */
-	{"gest", DTZ, POS(20)},		/* Georgia Summer Time */
-	{"get", TZ, POS(16)},		/* Georgia Time */
-	{"gft", TZ, NEG(12)},		/* French Guiana Time */
+	{"fst", TZ, 3600},			/* French Summer Time */
+	{"fwt", DTZ, 7200},			/* French Winter Time  */
+	{"galt", TZ, -21600},		/* Galapagos Time */
+	{"gamt", TZ, -32400},		/* Gambier Time */
+	{"gest", DTZ, 18000},		/* Georgia Summer Time */
+	{"get", TZ, 14400},			/* Georgia Time */
+	{"gft", TZ, -10800},		/* French Guiana Time */
 #if 0
 	ghst
 #endif
-	{"gilt", TZ, POS(48)},		/* Gilbert Islands Time */
-	{"gmt", TZ, POS(0)},		/* Greenwish Mean Time */
-	{"gst", TZ, POS(40)},		/* Guam Std Time, USSR Zone 9 */
-	{"gyt", TZ, NEG(16)},		/* Guyana Time */
+	{"gilt", TZ, 43200},		/* Gilbert Islands Time */
+	{"gmt", TZ, 0},				/* Greenwish Mean Time */
+	{"gst", TZ, 36000},			/* Guam Std Time, USSR Zone 9 */
+	{"gyt", TZ, -14400},		/* Guyana Time */
 	{"h", UNITS, DTK_HOUR},		/* "hour" */
 #if 0
 	hadt
 	hast
 #endif
-	{"hdt", DTZ, NEG(36)},		/* Hawaii/Alaska Daylight Time */
+	{"hdt", DTZ, -32400},		/* Hawaii/Alaska Daylight Time */
 #if 0
 	hkst
 #endif
-	{"hkt", TZ, POS(32)},		/* Hong Kong Time */
+	{"hkt", TZ, 28800},			/* Hong Kong Time */
 #if 0
-	{"hmt", TZ, POS(12)},		/* Hellas ? ? */
+	{"hmt", TZ, 10800},			/* Hellas ? ? */
 	hovst
 	hovt
 #endif
-	{"hst", TZ, NEG(40)},		/* Hawaii Std Time */
+	{"hst", TZ, -36000},		/* Hawaii Std Time */
 #if 0
 	hwt
 #endif
-	{"ict", TZ, POS(28)},		/* Indochina Time */
-	{"idle", TZ, POS(48)},		/* Intl. Date Line, East */
-	{"idlw", TZ, NEG(48)},		/* Intl. Date Line, West */
+	{"ict", TZ, 25200},			/* Indochina Time */
+	{"idle", TZ, 43200},		/* Intl. Date Line, East */
+	{"idlw", TZ, -43200},		/* Intl. Date Line, West */
 #if 0
 	idt							/* Israeli, Iran, Indian Daylight Time */
 #endif
 	{LATE, RESERV, DTK_LATE},	/* "infinity" reserved for "late time" */
 	{INVALID, RESERV, DTK_INVALID},		/* "invalid" reserved for bad time */
-	{"iot", TZ, POS(20)},		/* Indian Chagos Time */
-	{"irkst", DTZ, POS(36)},	/* Irkutsk Summer Time */
-	{"irkt", TZ, POS(32)},		/* Irkutsk Time */
-	{"irt", TZ, POS(14)},		/* Iran Time */
+	{"iot", TZ, 18000},			/* Indian Chagos Time */
+	{"irkst", DTZ, 32400},		/* Irkutsk Summer Time */
+	{"irkt", TZ, 28800},		/* Irkutsk Time */
+	{"irt", TZ, 12600},			/* Iran Time */
 	{"isodow", RESERV, DTK_ISODOW},		/* ISO day of week, Sunday == 7 */
 #if 0
 	isst
 #endif
-	{"ist", TZ, POS(8)},		/* Israel */
-	{"it", TZ, POS(14)},		/* Iran Time */
+	{"ist", TZ, 7200},			/* Israel */
+	{"it", TZ, 12600},			/* Iran Time */
 	{"j", UNITS, DTK_JULIAN},
 	{"jan", MONTH, 1},
 	{"january", MONTH, 1},
-	{"javt", TZ, POS(28)},		/* Java Time (07:00? see JT) */
-	{"jayt", TZ, POS(36)},		/* Jayapura Time (Indonesia) */
+	{"javt", TZ, 25200},		/* Java Time (07:00? see JT) */
+	{"jayt", TZ, 32400},		/* Jayapura Time (Indonesia) */
 	{"jd", UNITS, DTK_JULIAN},
-	{"jst", TZ, POS(36)},		/* Japan Std Time,USSR Zone 8 */
-	{"jt", TZ, POS(30)},		/* Java Time (07:30? see JAVT) */
+	{"jst", TZ, 32400},			/* Japan Std Time,USSR Zone 8 */
+	{"jt", TZ, 27000},			/* Java Time (07:30? see JAVT) */
 	{"jul", MONTH, 7},
 	{"julian", UNITS, DTK_JULIAN},
 	{"july", MONTH, 7},
 	{"jun", MONTH, 6},
 	{"june", MONTH, 6},
-	{"kdt", DTZ, POS(40)},		/* Korea Daylight Time */
-	{"kgst", DTZ, POS(24)},		/* Kyrgyzstan Summer Time */
-	{"kgt", TZ, POS(20)},		/* Kyrgyzstan Time */
-	{"kost", TZ, POS(48)},		/* Kosrae Time */
-	{"krast", DTZ, POS(28)},	/* Krasnoyarsk Summer Time */
-	{"krat", TZ, POS(32)},		/* Krasnoyarsk Standard Time */
-	{"kst", TZ, POS(36)},		/* Korea Standard Time */
-	{"lhdt", DTZ, POS(44)},		/* Lord Howe Daylight Time, Australia */
-	{"lhst", TZ, POS(42)},		/* Lord Howe Standard Time, Australia */
-	{"ligt", TZ, POS(40)},		/* From Melbourne, Australia */
-	{"lint", TZ, POS(56)},		/* Line Islands Time (Kiribati; +14 hours!) */
-	{"lkt", TZ, POS(24)},		/* Lanka Time */
+	{"kdt", DTZ, 36000},		/* Korea Daylight Time */
+	{"kgst", DTZ, 21600},		/* Kyrgyzstan Summer Time */
+	{"kgt", TZ, 18000},			/* Kyrgyzstan Time */
+	{"kost", TZ, 43200},		/* Kosrae Time */
+	{"krast", DTZ, 25200},		/* Krasnoyarsk Summer Time */
+	{"krat", TZ, 28800},		/* Krasnoyarsk Standard Time */
+	{"kst", TZ, 32400},			/* Korea Standard Time */
+	{"lhdt", DTZ, 39600},		/* Lord Howe Daylight Time, Australia */
+	{"lhst", TZ, 37800},		/* Lord Howe Standard Time, Australia */
+	{"ligt", TZ, 36000},		/* From Melbourne, Australia */
+	{"lint", TZ, 50400},		/* Line Islands Time (Kiribati; +14 hours!) */
+	{"lkt", TZ, 21600},			/* Lanka Time */
 	{"m", UNITS, DTK_MONTH},	/* "month" for ISO input */
-	{"magst", DTZ, POS(48)},	/* Magadan Summer Time */
-	{"magt", TZ, POS(44)},		/* Magadan Time */
+	{"magst", DTZ, 43200},		/* Magadan Summer Time */
+	{"magt", TZ, 39600},		/* Magadan Time */
 	{"mar", MONTH, 3},
 	{"march", MONTH, 3},
-	{"mart", TZ, NEG(38)},		/* Marquesas Time */
-	{"mawt", TZ, POS(24)},		/* Mawson, Antarctica */
+	{"mart", TZ, -34200},		/* Marquesas Time */
+	{"mawt", TZ, 21600},		/* Mawson, Antarctica */
 	{"may", MONTH, 5},
-	{"mdt", DTZ, NEG(24)},		/* Mountain Daylight Time */
-	{"mest", DTZ, POS(8)},		/* Middle Europe Summer Time */
-	{"met", TZ, POS(4)},		/* Middle Europe Time */
-	{"metdst", DTZ, POS(8)},	/* Middle Europe Daylight Time */
-	{"mewt", TZ, POS(4)},		/* Middle Europe Winter Time */
-	{"mez", TZ, POS(4)},		/* Middle Europe Zone */
-	{"mht", TZ, POS(48)},		/* Kwajalein */
+	{"mdt", DTZ, -21600},		/* Mountain Daylight Time */
+	{"mest", DTZ, 7200},		/* Middle Europe Summer Time */
+	{"met", TZ, 3600},			/* Middle Europe Time */
+	{"metdst", DTZ, 7200},		/* Middle Europe Daylight Time */
+	{"mewt", TZ, 3600},			/* Middle Europe Winter Time */
+	{"mez", TZ, 3600},			/* Middle Europe Zone */
+	{"mht", TZ, 43200},			/* Kwajalein */
 	{"mm", UNITS, DTK_MINUTE},	/* "minute" for ISO input */
-	{"mmt", TZ, POS(26)},		/* Myannar Time */
+	{"mmt", TZ, 23400},			/* Myannar Time */
 	{"mon", DOW, 1},
 	{"monday", DOW, 1},
 #if 0
 	most
 #endif
-	{"mpt", TZ, POS(40)},		/* North Mariana Islands Time */
-	{"msd", DTZ, POS(16)},		/* Moscow Summer Time */
-	{"msk", TZ, POS(12)},		/* Moscow Time */
-	{"mst", TZ, NEG(28)},		/* Mountain Standard Time */
-	{"mt", TZ, POS(34)},		/* Moluccas Time */
-	{"mut", TZ, POS(16)},		/* Mauritius Island Time */
-	{"mvt", TZ, POS(20)},		/* Maldives Island Time */
-	{"myt", TZ, POS(32)},		/* Malaysia Time */
+	{"mpt", TZ, 36000},			/* North Mariana Islands Time */
+	{"msd", DTZ, 14400},		/* Moscow Summer Time */
+	{"msk", TZ, 10800},			/* Moscow Time */
+	{"mst", TZ, -25200},		/* Mountain Standard Time */
+	{"mt", TZ, 30600},			/* Moluccas Time */
+	{"mut", TZ, 14400},			/* Mauritius Island Time */
+	{"mvt", TZ, 18000},			/* Maldives Island Time */
+	{"myt", TZ, 28800},			/* Malaysia Time */
 #if 0
 	ncst
 #endif
-	{"nct", TZ, POS(44)},		/* New Caledonia Time */
-	{"ndt", DTZ, NEG(10)},		/* Nfld. Daylight Time */
-	{"nft", TZ, NEG(14)},		/* Newfoundland Standard Time */
-	{"nor", TZ, POS(4)},		/* Norway Standard Time */
+	{"nct", TZ, 39600},			/* New Caledonia Time */
+	{"ndt", DTZ, -9000},		/* Nfld. Daylight Time */
+	{"nft", TZ, -12600},		/* Newfoundland Standard Time */
+	{"nor", TZ, 3600},			/* Norway Standard Time */
 	{"nov", MONTH, 11},
 	{"november", MONTH, 11},
-	{"novst", DTZ, POS(28)},	/* Novosibirsk Summer Time */
-	{"novt", TZ, POS(24)},		/* Novosibirsk Standard Time */
+	{"novst", DTZ, 25200},		/* Novosibirsk Summer Time */
+	{"novt", TZ, 21600},		/* Novosibirsk Standard Time */
 	{NOW, RESERV, DTK_NOW},		/* current transaction time */
-	{"npt", TZ, POS(23)},		/* Nepal Standard Time (GMT-5:45) */
-	{"nst", TZ, NEG(14)},		/* Nfld. Standard Time */
-	{"nt", TZ, NEG(44)},		/* Nome Time */
-	{"nut", TZ, NEG(44)},		/* Niue Time */
-	{"nzdt", DTZ, POS(52)},		/* New Zealand Daylight Time */
-	{"nzst", TZ, POS(48)},		/* New Zealand Standard Time */
-	{"nzt", TZ, POS(48)},		/* New Zealand Time */
+	{"npt", TZ, 20700},			/* Nepal Standard Time (GMT-5:45) */
+	{"nst", TZ, -12600},		/* Nfld. Standard Time */
+	{"nt", TZ, -39600},			/* Nome Time */
+	{"nut", TZ, -39600},		/* Niue Time */
+	{"nzdt", DTZ, 46800},		/* New Zealand Daylight Time */
+	{"nzst", TZ, 43200},		/* New Zealand Standard Time */
+	{"nzt", TZ, 43200},			/* New Zealand Time */
 	{"oct", MONTH, 10},
 	{"october", MONTH, 10},
-	{"omsst", DTZ, POS(28)},	/* Omsk Summer Time */
-	{"omst", TZ, POS(24)},		/* Omsk Time */
+	{"omsst", DTZ, 25200},		/* Omsk Summer Time */
+	{"omst", TZ, 21600},		/* Omsk Time */
 	{"on", IGNORE_DTF, 0},		/* "on" (throwaway) */
-	{"pdt", DTZ, NEG(28)},		/* Pacific Daylight Time */
+	{"pdt", DTZ, -25200},		/* Pacific Daylight Time */
 #if 0
 	pest
 #endif
-	{"pet", TZ, NEG(20)},		/* Peru Time */
-	{"petst", DTZ, POS(52)},	/* Petropavlovsk-Kamchatski Summer Time */
-	{"pett", TZ, POS(48)},		/* Petropavlovsk-Kamchatski Time */
-	{"pgt", TZ, POS(40)},		/* Papua New Guinea Time */
-	{"phot", TZ, POS(52)},		/* Phoenix Islands (Kiribati) Time */
+	{"pet", TZ, -18000},		/* Peru Time */
+	{"petst", DTZ, 46800},		/* Petropavlovsk-Kamchatski Summer Time */
+	{"pett", TZ, 43200},		/* Petropavlovsk-Kamchatski Time */
+	{"pgt", TZ, 36000},			/* Papua New Guinea Time */
+	{"phot", TZ, 46800},		/* Phoenix Islands (Kiribati) Time */
 #if 0
 	phst
 #endif
-	{"pht", TZ, POS(32)},		/* Philippine Time */
-	{"pkt", TZ, POS(20)},		/* Pakistan Time */
+	{"pht", TZ, 28800},			/* Philippine Time */
+	{"pkt", TZ, 18000},			/* Pakistan Time */
 	{"pm", AMPM, PM},
-	{"pmdt", DTZ, NEG(8)},		/* Pierre & Miquelon Daylight Time */
+	{"pmdt", DTZ, -7200},		/* Pierre & Miquelon Daylight Time */
 #if 0
 	pmst
 #endif
-	{"pont", TZ, POS(44)},		/* Ponape Time (Micronesia) */
-	{"pst", TZ, NEG(32)},		/* Pacific Standard Time */
-	{"pwt", TZ, POS(36)},		/* Palau Time */
-	{"pyst", DTZ, NEG(12)},		/* Paraguay Summer Time */
-	{"pyt", TZ, NEG(16)},		/* Paraguay Time */
-	{"ret", DTZ, POS(16)},		/* Reunion Island Time */
+	{"pont", TZ, 39600},		/* Ponape Time (Micronesia) */
+	{"pst", TZ, -28800},		/* Pacific Standard Time */
+	{"pwt", TZ, 32400},			/* Palau Time */
+	{"pyst", DTZ, -10800},		/* Paraguay Summer Time */
+	{"pyt", TZ, -14400},		/* Paraguay Time */
+	{"ret", DTZ, 14400},		/* Reunion Island Time */
 	{"s", UNITS, DTK_SECOND},	/* "seconds" for ISO input */
-	{"sadt", DTZ, POS(42)},		/* S. Australian Dayl. Time */
+	{"sadt", DTZ, 37800},		/* S. Australian Dayl. Time */
 #if 0
 	samst
 	samt
 #endif
-	{"sast", TZ, POS(38)},		/* South Australian Std Time */
+	{"sast", TZ, 34200},		/* South Australian Std Time */
 	{"sat", DOW, 6},
 	{"saturday", DOW, 6},
 #if 0
 	sbt
 #endif
-	{"sct", DTZ, POS(16)},		/* Mahe Island Time */
+	{"sct", DTZ, 14400},		/* Mahe Island Time */
 	{"sep", MONTH, 9},
 	{"sept", MONTH, 9},
 	{"september", MONTH, 9},
-	{"set", TZ, NEG(4)},		/* Seychelles Time ?? */
+	{"set", TZ, -3600},			/* Seychelles Time ?? */
 #if 0
 	sgt
 #endif
-	{"sst", DTZ, POS(8)},		/* Swedish Summer Time */
+	{"sst", DTZ, 7200},			/* Swedish Summer Time */
 	{"sun", DOW, 0},
 	{"sunday", DOW, 0},
-	{"swt", TZ, POS(4)},		/* Swedish Winter Time */
+	{"swt", TZ, 3600},			/* Swedish Winter Time */
 #if 0
 	syot
 #endif
 	{"t", ISOTIME, DTK_TIME},	/* Filler for ISO time fields */
-	{"tft", TZ, POS(20)},		/* Kerguelen Time */
-	{"that", TZ, NEG(40)},		/* Tahiti Time */
+	{"tft", TZ, 18000},			/* Kerguelen Time */
+	{"that", TZ, -36000},		/* Tahiti Time */
 	{"thu", DOW, 4},
 	{"thur", DOW, 4},
 	{"thurs", DOW, 4},
 	{"thursday", DOW, 4},
-	{"tjt", TZ, POS(20)},		/* Tajikistan Time */
-	{"tkt", TZ, NEG(40)},		/* Tokelau Time */
-	{"tmt", TZ, POS(20)},		/* Turkmenistan Time */
+	{"tjt", TZ, 18000},			/* Tajikistan Time */
+	{"tkt", TZ, -36000},		/* Tokelau Time */
+	{"tmt", TZ, 18000},			/* Turkmenistan Time */
 	{TODAY, RESERV, DTK_TODAY}, /* midnight */
 	{TOMORROW, RESERV, DTK_TOMORROW},	/* tomorrow midnight */
 #if 0
 	tost
 #endif
-	{"tot", TZ, POS(52)},		/* Tonga Time */
+	{"tot", TZ, 46800},			/* Tonga Time */
 #if 0
 	tpt
 #endif
-	{"truk", TZ, POS(40)},		/* Truk Time */
+	{"truk", TZ, 36000},		/* Truk Time */
 	{"tue", DOW, 2},
 	{"tues", DOW, 2},
 	{"tuesday", DOW, 2},
-	{"tvt", TZ, POS(48)},		/* Tuvalu Time */
+	{"tvt", TZ, 43200},			/* Tuvalu Time */
 #if 0
 	uct
 #endif
-	{"ulast", DTZ, POS(36)},	/* Ulan Bator Summer Time */
-	{"ulat", TZ, POS(32)},		/* Ulan Bator Time */
+	{"ulast", DTZ, 32400},		/* Ulan Bator Summer Time */
+	{"ulat", TZ, 28800},		/* Ulan Bator Time */
 	{"undefined", RESERV, DTK_INVALID}, /* pre-v6.1 invalid time */
-	{"ut", TZ, POS(0)},
-	{"utc", TZ, POS(0)},
-	{"uyst", DTZ, NEG(8)},		/* Uruguay Summer Time */
-	{"uyt", TZ, NEG(12)},		/* Uruguay Time */
-	{"uzst", DTZ, POS(24)},		/* Uzbekistan Summer Time */
-	{"uzt", TZ, POS(20)},		/* Uzbekistan Time */
-	{"vet", TZ, NEG(16)},		/* Venezuela Time */
-	{"vlast", DTZ, POS(44)},	/* Vladivostok Summer Time */
-	{"vlat", TZ, POS(40)},		/* Vladivostok Time */
+	{"ut", TZ, 0},
+	{"utc", TZ, 0},
+	{"uyst", DTZ, -7200},		/* Uruguay Summer Time */
+	{"uyt", TZ, -10800},		/* Uruguay Time */
+	{"uzst", DTZ, 21600},		/* Uzbekistan Summer Time */
+	{"uzt", TZ, 18000},			/* Uzbekistan Time */
+	{"vet", TZ, -14400},		/* Venezuela Time */
+	{"vlast", DTZ, 39600},		/* Vladivostok Summer Time */
+	{"vlat", TZ, 36000},		/* Vladivostok Time */
 #if 0
 	vust
 #endif
-	{"vut", TZ, POS(44)},		/* Vanuata Time */
-	{"wadt", DTZ, POS(32)},		/* West Australian DST */
-	{"wakt", TZ, POS(48)},		/* Wake Time */
+	{"vut", TZ, 39600},			/* Vanuata Time */
+	{"wadt", DTZ, 28800},		/* West Australian DST */
+	{"wakt", TZ, 43200},		/* Wake Time */
 #if 0
 	warst
 #endif
-	{"wast", TZ, POS(28)},		/* West Australian Std Time */
-	{"wat", TZ, NEG(4)},		/* West Africa Time */
-	{"wdt", DTZ, POS(36)},		/* West Australian DST */
+	{"wast", TZ, 25200},		/* West Australian Std Time */
+	{"wat", TZ, -3600},			/* West Africa Time */
+	{"wdt", DTZ, 32400},		/* West Australian DST */
 	{"wed", DOW, 3},
 	{"wednesday", DOW, 3},
 	{"weds", DOW, 3},
-	{"west", DTZ, POS(4)},		/* Western Europe Summer Time */
-	{"wet", TZ, POS(0)},		/* Western Europe */
-	{"wetdst", DTZ, POS(4)},	/* Western Europe Daylight Savings Time */
-	{"wft", TZ, POS(48)},		/* Wallis and Futuna Time */
-	{"wgst", DTZ, NEG(8)},		/* West Greenland Summer Time */
-	{"wgt", TZ, NEG(12)},		/* West Greenland Time */
-	{"wst", TZ, POS(32)},		/* West Australian Standard Time */
+	{"west", DTZ, 3600},		/* Western Europe Summer Time */
+	{"wet", TZ, 0},				/* Western Europe */
+	{"wetdst", DTZ, 3600},		/* Western Europe Daylight Savings Time */
+	{"wft", TZ, 43200},			/* Wallis and Futuna Time */
+	{"wgst", DTZ, -7200},		/* West Greenland Summer Time */
+	{"wgt", TZ, -10800},		/* West Greenland Time */
+	{"wst", TZ, 28800},			/* West Australian Standard Time */
 	{"y", UNITS, DTK_YEAR},		/* "year" for ISO input */
-	{"yakst", DTZ, POS(40)},	/* Yakutsk Summer Time */
-	{"yakt", TZ, POS(36)},		/* Yakutsk Time */
-	{"yapt", TZ, POS(40)},		/* Yap Time (Micronesia) */
-	{"ydt", DTZ, NEG(32)},		/* Yukon Daylight Time */
-	{"yekst", DTZ, POS(24)},	/* Yekaterinburg Summer Time */
-	{"yekt", TZ, POS(20)},		/* Yekaterinburg Time */
+	{"yakst", DTZ, 36000},		/* Yakutsk Summer Time */
+	{"yakt", TZ, 32400},		/* Yakutsk Time */
+	{"yapt", TZ, 36000},		/* Yap Time (Micronesia) */
+	{"ydt", DTZ, -28800},		/* Yukon Daylight Time */
+	{"yekst", DTZ, 21600},		/* Yekaterinburg Summer Time */
+	{"yekt", TZ, 18000},		/* Yekaterinburg Time */
 	{YESTERDAY, RESERV, DTK_YESTERDAY}, /* yesterday midnight */
-	{"yst", TZ, NEG(36)},		/* Yukon Standard Time */
-	{"z", TZ, POS(0)},			/* time zone tag per ISO-8601 */
-	{"zp4", TZ, NEG(16)},		/* UTC +4  hours. */
-	{"zp5", TZ, NEG(20)},		/* UTC +5  hours. */
-	{"zp6", TZ, NEG(24)},		/* UTC +6  hours. */
-	{ZULU, TZ, POS(0)},			/* UTC */
+	{"yst", TZ, -32400},		/* Yukon Standard Time */
+	{"z", TZ, 0},				/* time zone tag per ISO-8601 */
+	{"zp4", TZ, -14400},		/* UTC +4  hours. */
+	{"zp5", TZ, -18000},		/* UTC +5  hours. */
+	{"zp6", TZ, -21600},		/* UTC +6  hours. */
+	{ZULU, TZ, 0},				/* UTC */
 };
 
 static datetkn deltatktbl[] = {
@@ -521,9 +514,11 @@ datebsearch(char *key, datetkn *base, unsigned int nel)
 		while (last >= base)
 		{
 			position = base + ((last - base) >> 1);
-			result = key[0] - position->token[0];
+			/* precheck the first character for a bit of extra speed */
+			result = (int) key[0] - (int) position->token[0];
 			if (result == 0)
 			{
+				/* use strncmp so that we match truncated tokens */
 				result = strncmp(key, position->token, TOKMAXLEN);
 				if (result == 0)
 					return position;
@@ -547,6 +542,7 @@ DecodeUnits(int field, char *lowtoken, int *val)
 	int			type;
 	datetkn    *tp;
 
+	/* use strncmp so that we match truncated tokens */
 	if (deltacache[field] != NULL &&
 		strncmp(lowtoken, deltacache[field]->token, TOKMAXLEN) == 0)
 		tp = deltacache[field];
@@ -561,10 +557,7 @@ DecodeUnits(int field, char *lowtoken, int *val)
 	else
 	{
 		type = tp->type;
-		if (type == TZ || type == DTZ)
-			*val = FROMVAL(tp);
-		else
-			*val = tp->value;
+		*val = tp->value;
 	}
 
 	return type;
@@ -650,6 +643,7 @@ DecodeSpecial(int field, char *lowtoken, int *val)
 	int			type;
 	datetkn    *tp;
 
+	/* use strncmp so that we match truncated tokens */
 	if (datecache[field] != NULL &&
 		strncmp(lowtoken, datecache[field]->token, TOKMAXLEN) == 0)
 		tp = datecache[field];
@@ -668,18 +662,7 @@ DecodeSpecial(int field, char *lowtoken, int *val)
 	else
 	{
 		type = tp->type;
-		switch (type)
-		{
-			case TZ:
-			case DTZ:
-			case DTZMOD:
-				*val = FROMVAL(tp);
-				break;
-
-			default:
-				*val = tp->value;
-				break;
-		}
+		*val = tp->value;
 	}
 
 	return type;
@@ -1656,7 +1639,7 @@ DecodePosixTimezone(char *str, int *tzp)
 	{
 		case DTZ:
 		case TZ:
-			*tzp = (val * MINS_PER_HOUR) - tz;
+			*tzp = -(val + tz);
 			break;
 
 		default:
@@ -2308,7 +2291,7 @@ DecodeDateTime(char **field, int *ftype, int nf,
 						tm->tm_isdst = 1;
 						if (tzp == NULL)
 							return -1;
-						*tzp += val * MINS_PER_HOUR;
+						*tzp -= val;
 						break;
 
 					case DTZ:
@@ -2321,7 +2304,7 @@ DecodeDateTime(char **field, int *ftype, int nf,
 						tm->tm_isdst = 1;
 						if (tzp == NULL)
 							return -1;
-						*tzp = val * MINS_PER_HOUR;
+						*tzp = -val;
 						ftype[i] = DTK_TZ;
 						break;
 
@@ -2329,7 +2312,7 @@ DecodeDateTime(char **field, int *ftype, int nf,
 						tm->tm_isdst = 0;
 						if (tzp == NULL)
 							return -1;
-						*tzp = val * MINS_PER_HOUR;
+						*tzp = -val;
 						ftype[i] = DTK_TZ;
 						break;
 
@@ -3000,25 +2983,26 @@ PGTYPEStimestamp_defmt_scan(char **str, char *fmt, timestamp * d,
 				pfmt++;
 				scan_type = PGTYPES_TYPE_STRING_MALLOCED;
 				err = pgtypes_defmt_scan(&scan_val, scan_type, &pstr, pfmt);
-
-				/*
-				 * XXX use DecodeSpecial instead ? - it's declared static but
-				 * the arrays as well. :-(
-				 */
-				for (j = 0; !err && j < szdatetktbl; j++)
+				if (!err)
 				{
-					if (pg_strcasecmp(datetktbl[j].token, scan_val.str_val) == 0)
+					/*
+					 * XXX use DecodeSpecial instead?  Do we need strcasecmp
+					 * here?
+					 */
+					err = 1;
+					for (j = 0; j < szdatetktbl; j++)
 					{
-						/*
-						 * tz calculates the offset for the seconds, the
-						 * timezone value of the datetktbl table is in quarter
-						 * hours
-						 */
-						*tz = -15 * MINS_PER_HOUR * datetktbl[j].value;
-						break;
+						if ((datetktbl[j].type == TZ || datetktbl[j].type == DTZ) &&
+							pg_strcasecmp(datetktbl[j].token,
+										  scan_val.str_val) == 0)
+						{
+							*tz = -datetktbl[j].value;
+							err = 0;
+							break;
+						}
 					}
+					free(scan_val.str_val);
 				}
-				free(scan_val.str_val);
 				break;
 			case '+':
 				/* XXX */