Hello, Updating with the given zoneinfo [Asia/Dhaka] datafile changing nothing but the time initial BDT to BDST. I've tried to edit the earlier data file [tzdata2009i.tar.gz] and with little change found following: $zdump -v /etc/localtime | grep 2009 /etc/localtime Fri Jun 19 16:59:59 2009 UTC = Fri Jun 19 22:59:59 2009 BDT isdst=0 gmtoff=21600 /etc/localtime Fri Jun 19 17:00:00 2009 UTC = Sat Jun 20 00:00:00 2009 BDST isdst=1 gmtoff=25200 /etc/localtime Tue Sep 29 16:59:59 2009 UTC = Tue Sep 29 23:59:59 2009 BDST isdst=1 gmtoff=25200 /etc/localtime Tue Sep 29 17:00:00 2009 UTC = Tue Sep 29 23:00:00 2009 BDT isdst=0 gmtoff=21600 #Here is the tzdata/asia file # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Bang 2009 only - Jan 1 0:00 0 - Rule Bang 2009 only - Jun 19 23:00 1:00 S Rule Bang 2009 only - Sep 30 00:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Dhaka 6:01:40 - LMT 1890 5:53:20 - HMT 1941 Oct # Howrah Mean Time? 6:30 - BURT 1942 May 15 # Burma Time 5:30 - IST 1942 Sep 6:30 - BURT 1951 Sep 30 6:00 - DACT 1971 Mar 26 # Dacca Time 6:00 Bang BD%sT But still having problem with backward. Thanks, -- Mohammed Zahid Hossain System Administrator & Head of Operation ====================================== Onenet Communications Limited(ABSCO) (The ISP division of OneTel) Bulu Ocean Tower (14th Floor) 40 Kemal Ataturk Avenue Banani, Dhaka-1213, Bangladesh. Tel: (880-2) 885-3164, 886-0861, 882-1486, 989-8391 Web: http://www.onenetbd.com/