Taanis Bechoros

All firstborn males fast today.

It is customary for fathers to fast on behalf of their firstborn sons who are not yet bar mitzvah.

It has become customary to participate in a siyum maseches, allowing the participants to partake in a seudas mitzvah and end their fast.

Although a firstborn boy under bar mitzvah does not fast, it is customary to bring him to shul to hear a siyum.

The first night of Pesach will be the last night to say kiddush levanah this month. However, since lechatchilah we avoid saying kiddush levanah on Shabbos and Yom Tov, say it tonight if possible (if you have not said it yet).