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       zic - time zone compiler


       zic  [  -v  ]  [ -d directory ] [ -l localtime ] [ -p posixrules ] [ -L
       leapsecondfilename ] [ -s ] [ -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:

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

       -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

       -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
       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
               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 portable 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
               abbreviation)  may  be  used  to  repeat  the value of the FROM

       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.
               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  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 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

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

       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.

             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  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

             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.   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  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.


       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), zdump(1)