The Hebrew Month of Adar (& Adar II)

The fixed calendar cycle was only introduced by Hillel the Second in the 4th century. Prior to that, leap years were decided on a year-to-year basis by the Sanhedrin. See chabad.org/library/article_cdo/aid/526875/jewish/The-Jewish-Calendar-Year.htm

The pattern is that a leap year occurs in years 3, 6, 8, 11, 14, 17, and 19. Reply

Purim remembers the miraculous salvation the decree of Haman in ancient Persia. It is celebrated in Adar, which is a month that usually falls out near March. See this article. Reply

The fixed calendar cycle was only introduced by Hillel the Second in the 4th century. Prior to that, leap years were decided on a year-to-year basis by the Sanhedrin. As such, it is impossible to know with any certainty which we’re leap years during that time period. See this link Reply

There is no direct reference, but it is implied. The Torah simultaneously describes certain holidays as occurring during certain seasons (see Deuteronomy 16:1), while also using lunar months. The only way to have lunar years but holidays in season is to add leap months. See chabad.org/library/article_cdo/aid/526875/jewish/The-Jewish-Calendar-Year.htm Reply