компилятор часовых поясов (timezone compiler)
Примечание (Note)
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.
If, for a particular timezone, a clock advance caused by the
start of daylight saving coincides with and is equal to a clock
retreat caused by a change in UT offset, zic
produces a single
transition to daylight saving at the new UT offset without any
change in local (wall clock) time. To get separate transitions
use multiple zone continuation lines specifying transition
instants using universal time.