Maybe you need to update DateTime::TimeZone

http://www.timeanddate.com/time/zone/israel/tel-aviv says since mar 25 DST +1h, or UTC+3H instead of the regular UTC+2H, agrees with https://en.wikipedia.org/wiki/Israel_Summer_Time#Summer_Time_Dates

DateTime is returning +3 for the timesone, so it is accurate

$ perl -MDateTime -le " print DateTime->now( qw[ time_zone Asia/Tel_Av
+iv ] )->strftime( q/%F-%H:%M:%S%z/) "
2016-03-30-06:04:01+0300

$ perl -MDateTime -le " print DateTime->now( qw[ time_zone GMT ] )->st
+rftime( q/%F-%H:%M:%S%z/) "
2016-03-30-03:05:58+0000
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