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ZIC(8)                    BSD System Manager's Manual                   ZIC(8)

     zic -- time zone compiler

     zic [--version] [-d directory] [-L leapsecondfilename] [-l localtime]
         [-p posixrules] [-s] [-v] [-y command] [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.

     These options are available:
     --version   Output version information and exit.
     -d directory
                 Create time conversion information files in the named direc-
                 tory rather than in the standard directory named below.
     -L 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.
     -l timezone
                 Use the given time zone as local time.  zic will act as if
                 the input contained a link line of the form
                       Link timezone  localtime
     -p timezone
                 Use the given time zone's rules when handling POSIX-format
                 time zone environment variables.  zic will act as if the
                 input contained a link line of the form
                       Link timezone  posixrules
     -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.
     -v          Complain if a year that appears in a data file is outside the
                 range of years representable by time(3) values.  Also com-
                 plain if a time of 24:00 (which cannot be handled by pre-1998
                 versions of zic) appears in the input.
     -y command  Use the given command rather than yearistype when checking
                 year types (see below).

                 Input lines are made up of fields.  Fields are separated from
                 one another by any number of white space characters.  Leading
                 and trailing white space on input lines is ignored.  An
                 unquoted sharp character (#) in the input introduces a com-
                 ment 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.  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 US   1967 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.
                           Any integer year can be supplied; the Gregorian
                           calendar is assumed.  The word minimum (or an
                           abbreviation) means the minimum year representable
                           as an integer.  The word maximum (or an abbrevia-
                           tion) means the maximum year representable as an
                           integer.  Rules can describe times that are not
                           representable as time values, with the unrepre-
                           sentable times ignored; this allows rules to be
                           portable among hosts with differing 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 some-
                           thing else, then zic executes the command

                           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.  Rec-
                           ognized 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 that 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
                                 1:28:14  time in hours, minutes, and seconds
                                 -        equivalent to 0
                           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 may 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
                 SAVE      Gives the amount of time to be added to local stan-
                           dard 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).
                 LETTER/S  Gives the ``variable part'' (for example, the ``S''
                           or ``D'' in ``EST'' or ``EDT'') of time zone abbre-
                           viations 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/Adelaide  9:30 Aus  CST  1971 Oct 31
                 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 for-
                             mat as the AT and SAVE fields of rule lines;
                             begin the field with a minus sign if time must be
                             subtracted from UTC.
                 RULES/SAVE  The name of the rule(s) that apply in the time
                             zone or, alternatively, 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.  Alternatively, 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.  If this
                             is specified, the time zone information is gener-
                             ated 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 has the
                 same form as a zone line except that the string ``Zone'' and
                 the name are omitted, as the continuation 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 continu-

                 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 alternative name
                 for that zone.

                 Except for continuation lines, lines may appear in any order
                 in the input.

                 Lines in the file that describes leap seconds have the fol-
                 lowing form:
                       Leap YEAR MONTH     DAY  HH:MM:SS  CORR R/S
                 For example:
                       Leap 1974 Dec  31   23:59:60  +    S
                 The YEAR, MONTH, DAY, and HH:MM:SS fields tell when the leap
                 second happened.  The CORR field should be ``+'' if a second
                 was added or ``-'' if a second was skipped.  The R/S field
                 should be (an abbreviation of) ``Stationary'' if the leap
                 second time given by the other fields should be interpreted
                 as UTC or (an abbreviation of) ``Rolling'' if the leap second
                 time given by the other fields should be interpreted as local
                 wall clock time.

     For areas with more than two types of local time, you may 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.

     /usr/share/zoneinfo - standard directory used for created files

     ctime(3), tzfile(5), zdump(8)

BSD                            December 20, 2003                           BSD