A/UX® Programmer's Reference Sections

tzfile(4) tzfile(4)
Each structure is written as a 4-byte value for t t gmt 0 f f of
type long, in a standard byte order, followed by aI-byte value
for tt isdst and a I-byte value for tt abbrind. In each
structure, tt_gmtoff gives the number of seconds to be added
to Greenwich mean time (GMn, 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.
Then there are tzh_leapcnt pairs of 4-byte values, written in a
standard byte order. The first value of each pair gives the time (as
returned by time(2» at which a leap second occurs; the second
gives the total number of leap seconds to be applied after the
given time. The pairs of values are sorted in ascending order by
time.
Finally, there are tzh ttisstdcnt standard/wall indicators,
each stored as a I-byte value. They tell whether the transition
times associated with local time types are specified as standard
time or wall-clock time and are used when a time-zone file is used
in handling POSIX-style time-zone environment variables.
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 0 or the time
argument is less than the first transitiontime recorded in the file.
SEE ALSO
ctime(3), tzic(1M), tzdump(1M).
2 February, 1990
RevisionC