zic(1M) SYSTEM ADMINISTRATION COMMANDS zic(1M)
NAME
zic - time zone compiler
SYNOPSIS
zic [ -v ] [ -d directory ] [ -l localtime ] [ 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 (#) in
the input introduces a comment which extends to the end of
the line the pound sign appears on. White space characters
and pound signs may be enclosed in double quotes (") if
they're 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.
A rule line has the form
Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
For example:
Rule USA 1969 1973 - Apr lastSun 2:00 1:00 D
The fields that make up a rule line are:
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 max-
imum (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) may be used to repeat the
value of the FROM field.
TYPE Gives the type of year in which the rule applies.
If TYPE is `-' then the rule applies in all years
between FROM and TO inclusive; if TYPE is uspres,
the rule applies in U.S. Presidential election
years; if TYPE is nonpres, the rule applies in years
other than U.S. Presidential election years. If
TYPE is something else, then zic executes the com-
mand
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zic(1M) SYSTEM ADMINISTRATION COMMANDS zic(1M)
yearistype year type
to check the type of a year: an exit status of zero
is taken to mean that the year is of the given type;
an exit status of one is taken to mean that the year
is not of the given type.
IN Names the month in which the rule takes effect.
Month names may be abbreviated.
ON Gives the day on which the rule takes effect.
Recognized forms include:
5 the fifth 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 may be abbreviated or
spelled out in full. Note: there must be no 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
Any of these forms may be followed by the letter w if the
given time is local ``wall clock'' time or s if the given
time is local ``standard'' time; in the absence of w or s,
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 (although, of course, the w
and s suffixes are not used).
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zic(1M) SYSTEM ADMINISTRATION COMMANDS zic(1M)
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.
A zone line has the form
Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL]
For example:
Zone Australia/South-west GMTOFF RULES/SAVE FORMAT
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 GMT 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 if time must be subtracted from GMT.
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. UNTIL The time at which the GMT 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 GMT offset and rule change until the time
specified.
The next line must be a ``continuation'' line; this
has the same form as a zone line except that the
string ``Zone'' and the name are omitted, as the con-
tinuation line will place information starting at the
time specified as the UNTIL field in the previous line
in the file used by the previous line. Continuation
lines may contain an UNTIL field, just as zone lines
do, indicating that the next line is a further con-
tinuation.
A link line has the form
Link LINK-FROM LINK-TO
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zic(1M) SYSTEM ADMINISTRATION COMMANDS zic(1M)
For example:
Link US/Eastern EST5EDT
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 may appear in any order
in the input.
OPTIONS
-v Complain if a year that appears in a data file is out-
side the range of years representable by system time
values (0:00:00 AM GMT, January 1, 1970, to 3:14:07 AM
GMT, January 19, 2038).
-d directory
Create time conversion information files in the direc-
tory directory rather than in the standard directory
/usr/lib/locale/TZ.
-l timezone
Use the time zone timezone as local time. zic will act
as if the file contained a link line of the form
Link timezone localtime
FILES
/usr/lib/locale/TZ standard directory used for created
files
SEE ALSO
time(1), ctime(3)
NOTE
For areas with more than two types of local time, you may
need to use local standard time in the AT field of the ear-
liest transition time's rule to ensure that the earliest
transition time recorded in the compiled file is correct.
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