The zdump command prints the current time for each
time zone (zonename) listed on the command line.
Specify zonename as the name of the time zone
database file relative to /usr/share/lib/zoneinfo.
Specifying an invalid time zone (zonename)
to zdump does not return an error, rather zdump uses GMT. This is consistent
with the behavior of the library calls; zdump reflects
the same behavior of the time routines in libc. See ctime(3C) and mktime(3C).
Displays the entire contents of the time
zone database file for zonename. Prints 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 time at
which the rules for computing local time change; the time at the highest
possible time value; and the time at one day less than the highest possible
time value. See mktime(3C)
and ctime(3C)
for information regarding time value (time_t). Each line
of output ends with isdst=1 if the given time is Daylight
Saving Time, or isdst=0 otherwise.
-c cutoffyear
Cuts off the verbose output near the start of the year cutoffyear.