ZIC(8) Maintenance Procedures ZIC(8)


zic - time zone compiler


zic [--version] [-s] [-v] [-l localtime] [-p posixrules]
[-d directory] [-y yearistype] [filename]...


zic reads text from the file(s) named on the command line and creates the
time conversion information files specified in this input. If a filename
is '-', the standard input is read.

Input lines are made up of fields. Fields are separated by any number of
white space characters. Leading and trailing white space on input lines
is ignored. A pound sign (#) indicates a comment that extends to the end
of the line. White space characters and pound signs can be enclosed
within double quotes (" ") 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, or link


A rule line has the form:

For example:


The fields that make up a rule line are:

Rule USA 1969 1973 - Apr lastSun 2:00 1:00 D

Gives the (arbitrary) name of the set of rules this rule is
part of.

Gives the first year in which the rule applies. The word
minimum (or an abbreviation) means the minimum year with a
representable time value. The word maximum (or an
abbreviation) means the maximum year with a representable
time value.

Gives the final year in which the rule applies. In addition
to minimum and maximum (as above), the word only (or an
abbreviation) can be used to repeat the value of the FROM

Gives the type of year in which the rule applies. If TYPE is:

The rule applies in all years between FROM and
TO, inclusive.

The rule applies in U.S. Presidential election

The rule applies in years other than U.S.
Presidential election years.

The rule applies to even-numbered years.

The rule applies to odd-numbered years.

If TYPE is something else, then zic will attempt to execute
the command

yearistype year type

to check the type of a year: an exit status of 0 means that
the year is of the given type; an exit status of 1 means that
the year is not of the given type. The yearistype command is
not currently provided in the Solaris environment.

Names the month in which the rule takes effect. Month names
can be abbreviated.

Gives the day on which the rule takes effect. Recognized
forms include:

the fifth day of the month

The last Sunday in the month

The last Monday in the month

First Sunday on or after the eighth

Last Sunday on or before the 25th

Names of days of the week can be abbreviated or spelled out
in full. Note: There cannot be spaces within the ON field.

Gives the time of day at which the rule takes effect.
Recognized forms include:

Time in hours

Time in hours and minutes

24-hour format time (for times after noon)

Time in hours, minutes, and seconds, where hour 0
is midnight at the start of the day and hour 24 is
midnight at the end of the day.

Any of these forms can be followed by the letter w if the
given time is local "wall clock" time; s if the given time is
local "standard" time; or u (or g or z) if the given time is
universal time. In the absence of an indicator, wall clock
time is assumed.

Gives the amount of time to be added to local standard time
when the rule is in effect. This field has the same format as
the AT field (without the w and s suffixes).

Gives the "variable part" (for example, the "S" or "D" in
"EST" or "EDT" of time zone abbreviations to be used when
this rule is in effect. If this field is '-', the variable
part is null.


A zone line has the form:


For example:

Zone Australia/SouthWest 9:30 - CST 1992 Mar 15 12:00
8:30 Aus CST

The fields that make up a zone line are:

The name of the time zone. This is the name used in
creating the time conversion information file for the zone.

The amount of time to add to UTC to get standard time in
this zone. This field has the same format as the AT and
SAVE fields of rule lines; begin the field with a minus
sign to subtract time from UTC.

The name of the rule(s) that apply in the time zone or,
alternately, an amount of time to add to local standard
time. If this field is `-', then standard time always
applies in the time zone.

The format for time zone abbreviations in this time zone.
The pair of characters %s is used to show where the
"variable part" of the time zone abbreviation goes.
Alternately, a slash (/) separates standard and daylight

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. The time of day has the same format as the
AT field of rule lines. 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.

The next line must be a "continuation" line. This line has
the same form as a zone line except that the string "Zone"
and the name are omitted. The continuation line places
information starting at the time specified as the UNTIL
field in the previous line in the file used by the previous
line. Continuation lines can contain an UNTIL field, just
as zone lines do, indicating that the next line is a
further continuation.


A link line has the form:


For example:

Link Europe/Istanbul Asia/Istanbul

The LINK-FROM field should appear as the NAME field in some zone line;
the LINK-TO field is used as an alternate name for that zone.

Except for continuation lines, lines can appear in any order in the


Outputs version information and exits.

-d directory
Creates time conversion information files in the
directory directory rather than in the standard
directory /usr/share/lib/zoneinfo.

-l localtime
Uses the given time zone as local time localtime. zic
acts as if the file contained a link line of the form:

Link localtime localtime

-p posixrules
Uses the rules of the given time zone posixrules when
handling POSIX-format time zone environment variables.
zic acts as if the input contained a link line of the

Link posixrules posixrules

This option is not used by ctime(3C) and mktime(3C) in
the Solaris environment.

Limits 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.

This option is obsolete and may be removed in a future

Complains if a year that appears in a data file is
outside the range of years representable by system time
values (0:00:00 a.m. UTC, January 1, 1970, to 3:14:07
a.m. UTC, January 19, 2038). This option also complains
if a time of 24:00 (which cannot be handled by
pre-1998 versions of zic) appears in the input.

-y yearistype
Uses the given command yearistype rather than yearistype
when checking year types (see Rules under DESCRIPTION).


A file containing input lines that specify the time
conversion information files to be created. If a filename is
'-', the standard input is read.



Standard directory used for created files


Directory containing source files


See attributes(7) for descriptions of the following attributes:

|Interface Stability | Committed* |

* The -s option is obsolete.


time(1), ctime(3C), mktime(3C), attributes(7), zdump(8)


For areas with more than two types of local time, you might need to use
local standard time in the AT field of the earliest transition time's
rule to ensure that the earliest transition time recorded in the compiled
file is correct.

If the current timezone file is edited and compiled using the "zic"
command, the changes will only be reflected in any new processes that are
running. The most accurate way to reflect the changes for the whole
system would be a reboot.

January 3, 2006 ZIC(8)