ZDUMP(8)ZDUMP(8)NAMEzdump - time zone dumper
SYNOPSISzdump [ --version ] [ -v ] [ -V ] [ -c [loyear,]hiyear ] [ -t
[lotime,]hitime ] [ zonename ... ]
DESCRIPTION
Zdump prints the current time in each zonename named on the command
line.
These options are available:
--version
Output version information and exit.
-v For each zonename on the command line, print the time at the
lowest possible time value, the time one day after the lowest
possible time value, the times both one second before and
exactly at each detected time discontinuity, the time at one day
less than the highest possible time value, and the time at the
highest possible time value, Each line ends with isdst=1 if the
given time is Daylight Saving Time or isdst=0 otherwise.
-V Like -v, except omit the times relative to the extreme time val‐
ues. This generates output that is easier to compare to that of
implementations with different time representations.
-c [loyear,]hiyear
Cut off verbose output near the start of the given year(s). By
default, the program cuts off verbose output near the starts of
the years -500 and 2500.
-t [lotime,]hitime
Cut off verbose output at the start of the given time(s), given
in decimal seconds since 1970-01-01 00:00:00 UTC.
LIMITATIONS
Time discontinuities are found by sampling the results returned by
localtime at twelve-hour intervals. This works in all real-world
cases; one can construct artificial time zones for which this fails.
In the output, "UT" denotes the value returned by gmtime(3), which uses
UTC for modern time stamps and some other UT flavor for time stamps
that predate the introduction of UTC. No attempt is currently made to
have the output use "UTC" for newer and "UT" for older time stamps,
partly because the exact date of the introduction of UTC is problem‐
atic.
SEE ALSOnewctime(3), tzfile(5), zic(8)ZDUMP(8)
