[net.misc] algorithm for summer time?

djmdavies (06/23/82)

Anyone got an algorithm for figuring out whether it is summer or winter
time, from the date?  I've got one, based on the hypothesis that the
summer-or daylight saving-time starts on the last Sunday in April, and
finishes on the last Sunday in October.  This seems to have been true for
the last few years, but can someone confirm that this is indeed a correct
working rule for the indefinite future?
  (Mail to me and I'll post if I get information)
Julian Davies