ZIC(8)                    Linux System Administration                   ZIC(8)

       zic - timezone compiler

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

       The  zic  program 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 -, standard input is read.

       These options are available:

       -d directory
              Create  time conversion information files in the named directory
              rather than in the standard directory named below.

       -l timezone
              Use the given timezone 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 timezone's rules when handling POSIX-format time-
              zone environment variables.  zic will act as if the  input  con-
              tained a link line of the form

            Link timezone       posixrules

       -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.

       -v     Complain  if  a  year that appears in a data file is outside the
              range of years representable by time(2) values.

       -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.

       -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 comment which extends to the end of the  line
       the sharp character appears on.  White space characters and sharp char-
       acters 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.  Nonblank 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 repre-
               sentable  as an integer.  The word maximum (or an abbreviation)
               means the maximum year representable as an integer.  Rules  can
               describe  times that are not representable as time values, with
               the unrepresentable times ignored; this allows rules to be por-
               table among hosts with differing time value types.

       TO      Gives the final year in which the rule applies.  In addition to
               minimum and maximum (as above), the word only (or an  abbrevia-
               tion) 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 something else, then zic executes the
                    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

       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.  Recog-
              nized 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
       -        equivalent to 0

       where hour 0 is midnight at the start of the day, and hour 24  is  mid-
       night 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 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).

              Gives  the "variable part" (for example, the "S" or "D" in "EST"
              or "EDT") of timezone 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                UTCOFF  RULES/SAVE  FORMAT  [UNTIL]

       For example:

            Zone  Australia/Adelaide  9:30    Aus         CST     1971 Oct 31 2:00

       The fields that make up a zone line are:

       NAME  The  name of the timezone.  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 if time must  be
             subtracted from UTC.

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

             The format for timezone abbreviations in this timezone.  The pair
             of characters %s is used to show where the "variable part" of the
             timezone  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.  If this is specified, the timezone 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 miss-
             ing 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 continuation.

       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 may appear in  any  order  in  the

       Lines in the file that describes leap seconds have the following 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.

              Standard directory used for created files.

       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 com-
       piled file is correct.

       tzfile(5), zdump(8)

       This page is part of release 4.15 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at

                                  2010-02-25                            ZIC(8)
Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2022 Hurricane Electric. All Rights Reserved.