I disagree.
I'm Israeli, we set DST at random intervals according to local politics, and I will sure to fail that test.
The jokes belong on Purim, Adar 14 according to the Hebrew calendar, and Adar 15 on ancient cities surrounded by walls. On leap yersyears, the Jewish calendar has another month - Adar A and Adar B, and Purim is held on Adar B. Of course, if that falls on a Sabbath, the holiday can be postponed by a day.
Now, implement that.