On Leap year the Jewish people celebrate the Hebrew month of ADAR twice.
We celebrate Purim Katan and "Shoshan Purim Katan", on ADAR I.
about 1600 years ago-359 BCE ourpresent fixed calendar was established and the Sanhedrin, the High Rabinical Court would add an extra month for the pilgrims to reach Jerusalem on Pessach, does giving the people plenty time to arrive from far away.
