Clocks change in Bulgaria to summer daylight saving time on March 31 2013
Summer daylight saving time starts in Bulgaria on March 31 2013 at 3am, when clocks must be adjusted forward an hour to 4am.
Daylight saving time starts every year on the last Sunday of March and ends on the last Sunday of October – in 2013, on October 27 – when clocks will again be reset, an hour back.