Tribblix: manual page: zic.8

ZIC(8) Maintenance Commands and Procedures ZIC(8)

NAME

zic - time zone compiler

SYNOPSIS

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

DESCRIPTION

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 lines.

Rule

A rule line has the form:

For example:

Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S

The fields that make up a rule line are:

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

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

FROM
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.

TO
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 field.

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

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

uspres
The rule applies in U.S. Presidential
election years.

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

even
The rule applies to even-numbered years.

odd
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.

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

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

5
the fifth day of the month

lastSun
The last Sunday in the month

lastMon
The last Monday in the month

Sun>=8
First Sunday on or after the eighth

Sun<=25
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.

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

2
Time in hours

2:00
Time in hours and minutes

15:00
24-hour format time (for times after noon)

1:28:14
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.

SAVE
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).

LETTER/S
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.

Zone

A zone line has the form:

Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL]

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:

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

GMTOFF
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.

RULES/SAVE
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.

FORMAT
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 abbreviations.

UNTIL
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.

Link

A link line has the form:

Link LINK-FROM LINK-TO

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
input.

OPTIONS

--version
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 form:

Link posixrules posixrules

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

-s
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 release.

-v
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).

OPERANDS

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

FILES

/usr/share/lib/zoneinfo

Standard directory used for created files

/usr/share/lib/zoneinfo/src

Directory containing source files

ATTRIBUTES

NOTES

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)