-.\" $FreeBSD: src/usr.sbin/zic/zic.8,v 1.17 2004/07/02 23:13:00 ru Exp $
+.\" $FreeBSD: head/contrib/tzcode/zic/zic.8 214411 2010-10-27 07:14:46Z edwin $
.Dd June 20, 2004
.Dt ZIC 8
.Os
.Nm zic
.Nd timezone compiler
.Sh SYNOPSIS
-.Nm zic
+.Nm
.Op Fl -version
.Op Fl Dsv
.Op Fl d Ar directory
.Op Ar filename ...
.Sh DESCRIPTION
The
-.Nm zic
+.Nm
utility reads text from the file(s) named on the command line
and creates the time conversion information files specified in this input.
If a
.Pp
The following options are available:
.Bl -tag -width indent
-.\" ==========
+.It Fl -version
+Output version information and exit.
.It Fl D
Do not automatically create directories.
If the input file(s) specify
If
.Fl D
is specified,
-.Nm zic
+.Nm
will instead error out immediately.
-.\" ==========
.It Fl d Ar directory
Create time conversion information files in the named directory rather than
in the standard directory named below.
-.\" ==========
.It Fl g Ar group
After creating each output file, change its group ownership to the
specified
.Ar group
(which can be either a name or a numeric group ID).
-.\" ==========
.It Fl L Ar leapsecondfilename
Read leap second information from the file with the given name.
If this option is not used,
no leap second information appears in output files.
-.\" ==========
.It Fl l Ar timezone
Use the given
.Ar time zone
as local time.
The
-.Nm zic
+.Nm
utility will act as if the input contained a link line of the form
-.Bd -literal -offset indent
-.No "Link timezone localtime
-.Ed
+.Pp
+.D1 No "Link timezone localtime"
+.Pp
(Note that this action has no effect on
.Fx ,
since the local time zone is specified in
.Pa /etc/localtime
and not
.Pa /usr/share/zoneinfo/localtime . )
-.\" ==========
.It Fl m Ar mode
After creating each output file, change its access mode to
.Ar mode .
Both numeric and alphabetic modes are accepted
(see
.Xr chmod 1 ) .
-.\" ==========
.It Fl p Ar timezone
Use the given
.Ar "time zone" Ns 's
rules when handling POSIX-format
time zone environment variables.
The
-.Nm zic
+.Nm
utility will act as if the input contained a link line of the form
-.Bd -literal -offset indent
-.No "Link timezone posixrules
-.Ed
-.\" ==========
-.It Fl s
-Limit time values stored in output files to values that are the same
-whether they're taken to be signed or unsigned.
-You can use this option to generate SVVS-compatible files.
-.\" ==========
+.Pp
+.D1 No "Link timezone posixrules"
.It Fl u Ar user
After creating each output file, change its owner to
.Ar user
of years representable by
.Xr time 3
values.
-.\" ==========
-.It Fl -version
-Output version information and exit.
-.\" ==========
+.It Fl s
+Limit time values stored in output files to values that are the same
+whether they are taken to be signed or unsigned.
+You can use this option to generate SVVS-compatible files.
.It Fl y Ar command
Use the given
.Ar command
An unquoted sharp character (#) in the input introduces a comment which extends
to the end of the line the sharp character appears on.
White space characters and sharp characters may be enclosed in double quotes
-(") if they're to be used as part of a field.
+(") if they are to be used as part of a field.
Any line that is blank (after comment stripping) is ignored.
Non-blank lines are expected to be of one of three types:
rule lines, zone lines, and link lines.
.Pp
+Names (such as month names) must be in English and are case insensitive.
+Abbreviations, if used, must be unambiguous in context.
+.Pp
A rule line has the form:
-.Dl "Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
+.Dl "Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S"
For example:
-.Dl "Rule US 1967 1973 \- Apr lastSun 2:00 1:00 D
+.Dl "Rule US 1967 1973 \- Apr lastSun 2:00 1:00 D"
.Pp
The fields that make up a rule line are:
.Bl -tag -width "LETTER/S" -offset indent
If
.Em TYPE
is something else, then
-.Nm zic
+.Nm
executes the command
.Li yearistype Ar year Ar type
to check the type of a year:
.El
.Pp
A zone line has the form:
-.Dl "Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL]
+.Dl "Zone NAME GMTOFF RULES/SAVE FORMAT [UNTILYEAR [MONTH [DAY [TIME]]]]"
For example:
-.Dl "Zone Australia/Adelaide 9:30 Aus CST 1971 Oct 31 2:00
+.Dl "Zone Australia/Adelaide 9:30 Aus CST 1971 Oct 31 2:00"
The fields that make up a zone line are:
.Bl -tag -width indent
.It NAME
Alternately,
a slash (/)
separates standard and daylight abbreviations.
-.It UNTIL
+.It UNTILYEAR [MONTH [DAY [TIME]]]
The time at which the UTC offset or the rule(s) change for a location.
It is specified as a year, a month, a day, and a time of day.
If this is specified,
the time zone information is generated from the given UTC offset
and rule change until the time specified.
The month, day, and time of day have the same format as the IN, ON, and AT
-columns of a rule; trailing columns can be omitted, and default to the
-earliest possible value for the missing columns.
+fields of a rule; trailing fields can be omitted, and default to the
+earliest possible value for the missing fields.
.Pp
The next line must be a
.Dq continuation
.Dq Zone
and the name are omitted, as the continuation line will
place information starting at the time specified as the
-.Em UNTIL
-field in the previous line in the file used by the previous line.
-Continuation lines may contain an
-.Em UNTIL
-field, just as zone lines do, indicating that the next line is a further
+.Em until
+information in the previous line in the file used by the previous line.
+Continuation lines may contain
+.Em until
+information, just as zone lines do, indicating that the next line is a further
continuation.
.El
.Pp
A link line has the form
-.Dl "Link LINK-FROM LINK-TO
+.Dl "Link LINK-FROM LINK-TO"
For example:
-.Dl "Link Europe/Istanbul Asia/Istanbul
+.Dl "Link Europe/Istanbul Asia/Istanbul"
The
.Em LINK-FROM
field should appear as the
lines may appear in any order in the input.
.Pp
Lines in the file that describes leap seconds have the following form:
-.Dl "Leap YEAR MONTH DAY HH:MM:SS CORR R/S
+.Dl "Leap YEAR MONTH DAY HH:MM:SS CORR R/S"
For example:
-.Dl "Leap 1974 Dec 31 23:59:60 + S
+.Dl "Leap 1974 Dec 31 23:59:60 + S"
The
.Em YEAR ,
.Em MONTH ,
.Dq Rolling
if the leap second time given by the other fields should be interpreted as
local wall clock time.
-.Sh NOTE
+.Sh "EXTENDED EXAMPLE"
+Here is an extended example of
+.Nm
+input, intended to illustrate many of its features.
+.br
+.ne 22
+.nf
+.in +2m
+.ta \w'# Rule\0\0'u +\w'NAME\0\0'u +\w'FROM\0\0'u +\w'1973\0\0'u +\w'TYPE\0\0'u +\w'Apr\0\0'u +\w'lastSun\0\0'u +\w'2:00\0\0'u +\w'SAVE\0\0'u
+.sp
+# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
+Rule Swiss 1940 only - Nov 2 0:00 1:00 S
+Rule Swiss 1940 only - Dec 31 0:00 0 -
+Rule Swiss 1941 1942 - May Sun>=1 2:00 1:00 S
+Rule Swiss 1941 1942 - Oct Sun>=1 0:00 0
+.sp .5
+Rule EU 1977 1980 - Apr Sun>=1 1:00u 1:00 S
+Rule EU 1977 only - Sep lastSun 1:00u 0 -
+Rule EU 1978 only - Oct 1 1:00u 0 -
+Rule EU 1979 1995 - Sep lastSun 1:00u 0 -
+Rule EU 1981 max - Mar lastSun 1:00u 1:00 S
+Rule EU 1996 max - Oct lastSun 1:00u 0 -
+.sp
+.ta \w'# Zone\0\0'u +\w'Europe/Zurich\0\0'u +\w'0:34:08\0\0'u +\w'RULES/SAVE\0\0'u +\w'FORMAT\0\0'u
+# Zone NAME GMTOFF RULES FORMAT UNTIL
+Zone Europe/Zurich 0:34:08 - LMT 1848 Sep 12
+ 0:29:44 - BMT 1894 Jun
+ 1:00 Swiss CE%sT 1981
+ 1:00 EU CE%sT
+.sp
+Link Europe/Zurich Switzerland
+.sp
+.in
+.fi
+In this example, the zone is named Europe/Zurich but it has an alias
+as Switzerland.
+Zurich was 34 minutes and 8 seconds west of GMT until 1848-09-12
+at 00:00, when the offset changed to 29 minutes and 44 seconds.
+After 1894-06-01 at 00:00 Swiss daylight saving rules (defined with
+lines beginning with "Rule Swiss") apply, and the GMT offset became
+one hour.
+From 1981 to the present, EU daylight saving rules have applied,
+and the UTC offset has remained at one hour.
+.Pp
+In 1940, daylight saving time applied from November 2 at 00:00 to
+December 31 at 00:00.
+In 1941 and 1942, daylight saving time applied from the first Sunday
+in May at 02:00 to the first Sunday in October at 00:00.
+The pre-1981 EU daylight-saving rules have no effect here, but are
+included for completeness.
+Since 1981, daylight saving has begun on the last Sunday in March
+at 01:00 UTC.
+Until 1995 it ended the last Sunday in September at 01:00 UTC, but
+this changed to the last Sunday in October starting in 1996.
+.Pp
+For purposes of display, "LMT" and "BMT" were initially used,
+respectively.
+Since Swiss rules and later EU rules were applied, the display name
+for the timezone has been CET for standard time and CEST for daylight
+saving time.
+.Sh NOTES
For areas with more than two types of local time,
you may need to use local standard time in the
.Em AT
field of the earliest transition time's rule to ensure that
the earliest transition time recorded in the compiled file is correct.
+.Pp
+If, for a particular zone, a clock advance caused by the start of
+daylight saving coincides with and is equal to a clock retreat
+caused by a change in UTC offset,
+.Nm
+produces a single transition to daylight saving at the new UTC offset
+(without any change in wall clock time).
+To get separate transitions use multiple zone continuation lines
+specifying transition instants using universal time.
.Sh FILES
.Bl -tag -width /usr/share/zoneinfo -compact
.It /usr/share/zoneinfo
.Xr ctime 3 ,
.Xr tzfile 5 ,
.Xr zdump 8
-.\" @(#)zic.8 7.18
+.\" @(#)zic.8 8.6
+.\" This file is in the public domain, so clarified as of
+.\" 2009-05-17 by Arthur David Olson.
projects / apple / system_cmds.git / blobdiff