Unix/Linux Go Back    

BSD 2.11 - man page for tzfile (bsd section 5)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)

TZFILE(5)										TZFILE(5)

       tzfile - time zone information

       #include <tzfile.h>

       The time zone information files used by tzset(3) begin with bytes reserved for future use,
       followed by three four-byte values of type long, written in a ``standard'' byte order (the
       high-order byte of the value is written first).	These values are, in order:

	      The number of "transition times" for which data is stored in the file.

	      The  number of "local time types" for which data is stored in the file (must not be

	      The number of characters of "time zone abbreviation strings" stored in the file.

       The above header is followed by tzh_timecnt four-byte  values  of  type	long,  sorted  in
       ascending  order.  These values are written in ``standard'' byte order.	Each is used as a
       transition time (as returned by time(2)) at which  the  rules  for  computing  local  time
       change.	Next come tzh_timecnt one-byte values of type unsigned char; each one tells which
       of the different types of ``local time'' types described in the file  is  associated  with
       the  same-indexed  transition time.  These values serve as indices into an array of ttinfo
       structures that appears next in the file; these structures are defined as follows:

	    struct ttinfo {
		 long	       tt_gmtoff;
		 int	       tt_isdst;
		 unsigned int  tt_abbrind;

       Each structure is written as a four-byte value for tt_gmtoff of type long, in  a  standard
       byte order, followed by a one-byte value for tt_isdst and a one-byte value for tt_abbrind.
       In each structure, tt_gmtoff gives the number of seconds to  be	added  to  GMT,  tt_isdst
       tells  whether  tm_isdst  should be set by localtime (3) and tt_abbrind serves as an index
       into the array of time zone abbreviation characters that follow the ttinfo structure(s) in
       the file.

       Localtime  uses	the first standard-time ttinfo structure in the file (or simply the first
       ttinfo structure in the absence of a standard-time structure)  if  either  tzh_timecnt  is
       zero or the time argument is less than the first transition time recorded in the file.


System V										TZFILE(5)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums

All times are GMT -4. The time now is 01:57 PM.