$ zdump -v /etc/localtime | grep 2009
/etc/localtime Thu Mar 26 23:59:59 2009 UTC = Fri Mar 27 01:59:59 2009 IST isdst=0 gmtoff=7200
/etc/localtime Fri Mar 27 00:00:00 2009 UTC = Fri Mar 27 03:00:00 2009 IDT isdst=1 gmtoff=10800
/etc/localtime Sat Sep 26 22:59:59 2009 UTC = Sun Sep 27 01:59:59 2009 IDT isdst=1 gmtoff=10800
/etc/localtime Sat Sep 26 23:00:00 2009 UTC = Sun Sep 27 01:00:00 2009 IST isdst=0 gmtoff=7200