When setting timezone, you can set interval of daylight saving time rule. In Slovakia, it is from last sunday of march up to last sunday of october, and change is being made at 2:00.
Configuration is made under regional tab on the bottom of the page. There is box “Daylight Saving Time Rule” and for Slovakia, you should put there:
start=3/-1/7/2;end=10/-1/7/2;save=1