Update timezone file description to match new zic (coming soon).

Update man page to reflect reality.

lib/libc/stdtime/tzfile.5

@@ -7,14 +7,19 @@ tzfile \- time zone information
 .SH DESCRIPTION
 The time zone information files used by
 .IR tzset (3)
-begin with bytes reserved for future use,
-followed by four four-byte values of type
+begin with the magic characters "TZif" to identify then as
+time zone information files,
+followed by sixteen bytes reserved for future use,
+followed by six four-byte values of type
 .BR long ,
 written in a ``standard'' byte order
 (the high-order byte of the value is written first).
 These values are,
 in order:
 .TP
+.I tzh_ttisgmtcnt
+The number of UTC/local indicators stored in the file.
+.TP
 .I tzh_ttisstdcnt
 The number of standard/wall indicators stored in the file.
 .TP
@@ -74,7 +79,7 @@ and a one-byte value for
 .IR tt_abbrind .
 In each structure,
 .I tt_gmtoff
-gives the number of seconds to be added to GMT,
+gives the number of seconds to be added to UTC,
 .I tt_isdst
 tells whether
 .I tm_isdst
@@ -99,7 +104,7 @@ the second gives the
 number of leap seconds to be applied after the given time.
 The pairs of values are sorted in ascending order by time.
 .PP
-Finally there are
+Then there are
 .I tzh_ttisstdcnt
 standard/wall indicators, each stored as a one-byte value;
 they tell whether the transition times associated with local time types
@@ -107,6 +112,14 @@ were specified as standard time or wall clock time,
 and are used when a time zone file is used in handling POSIX-style
 time zone environment variables.
 .PP
+Finally there are
+.I tzh_ttisgmtcnt
+UTC/local indicators, each stored as a one-byte value;
+they tell whether the transition times associated with local time types
+were specified as UTC or local time,
+and are used when a time zone file is used in handling POSIX-style
+time zone environment variables.
+.PP
 .I Localtime
 uses the first standard-time
 .I ttinfo
@@ -120,4 +133,6 @@ is zero or the time argument is less than the first transition time recorded
 in the file.
 .SH SEE ALSO
 newctime(3)
-.\" @(#)tzfile.5	7.2
+.\" @(#)tzfile.5	7.11
+.\" This file is in the public domain, so clarified as of
+.\" 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).

lib/libc/stdtime/tzfile.h

@@ -4,7 +4,7 @@
 
 /*
 ** This file is in the public domain, so clarified as of
-** June 5, 1996 by Arthur David Olson (arthur_david_olson@nih.gov).
+** 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
 */
 
 /*
@@ -21,7 +21,7 @@
 
 #ifndef lint
 #ifndef NOID
-static char	tzfilehid[] = "@(#)tzfile.h	7.8";
+static char	tzfilehid[] = "@(#)tzfile.h	7.14";
 #endif /* !defined NOID */
 #endif /* !defined lint */
 
@@ -45,8 +45,11 @@ static char	tzfilehid[] = "@(#)tzfile.h	7.8";
 ** Each file begins with. . .
 */
 
+#define	TZ_MAGIC	"TZif"
+
 struct tzhead {
-	char	tzh_reserved[20];	/* reserved for future use */
+ 	char	tzh_magic[4];		/* TZ_MAGIC */
+	char	tzh_reserved[16];	/* reserved for future use */
 	char	tzh_ttisgmtcnt[4];	/* coded number of trans. time flags */
 	char	tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
 	char	tzh_leapcnt[4];		/* coded number of leap seconds */
@@ -61,7 +64,7 @@ struct tzhead {
 **	tzh_timecnt (char [4])s		coded transition times a la time(2)
 **	tzh_timecnt (unsigned char)s	types of local time starting at above
 **	tzh_typecnt repetitions of
-**		one (char [4])		coded GMT offset in seconds
+**		one (char [4])		coded UTC offset in seconds
 **		one (unsigned char)	used to set tm_isdst
 **		one (unsigned char)	that's an abbreviation list index
 **	tzh_charcnt (char)s		'\0'-terminated zone abbreviations
@@ -74,7 +77,7 @@ struct tzhead {
 **					if absent, transition times are
 **					assumed to be wall clock time
 **	tzh_ttisgmtcnt (char)s		indexed by type; if TRUE, transition
-**					time is GMT, if FALSE,
+**					time is UTC, if FALSE,
 **					transition time is local time
 **					if absent, transition times are
 **					assumed to be local time