Jewish holy days (chaggim), celebrate landmark events in Jewish history, such as the Exodus from Egypt and the giving of the Torah, and sometimes mark the change of seasons and transitions in the agricultural cycle.
The three major festivals, Sukkot, Passover and Shavuot, are called "regalim" (derived from the Hebrew word "regel", or foot).
On the three regalim, it was customary for the Israelites to make pilgrimages to Jerusalem to offer sacrifices in the Temple.