Major changes from tzdata2011b to tzdata2011c:
africa
Summer time changes for Morocco (to start late April 2012)
asia
Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
northamerica
Haiti following US/Canada rules for 2012 (and we're assuming,
for now anyway, for the future).
Major changes from tzdata2011c to tzdata2011d:
Morocco does not observe DST from Jul 20 03:00 to
Aug 20 02:00 [2012].
Infrastructure changes to accommodate how the tz
code and data are released on IANA.