Kenneth Cohen

Leap Year

We are now coming to the end of the month known as Adar II. It is the extra month that is added seven times every 19 years, in order to keep the solar and lunar calendar in balance.

Since the end of the Sanhedrin in 358 CE, there has been a set calendar. We know exactly which years are leap years and which are not. Before the establishment of the set calendar, the decision to add an extra month of Adar, was made on the basis of various criteria.

There were times when it was already obvious on Succot that an extra month would need to be added. They could see that the autumnal equinox fell during Succot. If an extra Adar was not added, Pesach would not fall in spring.

The Talmud in Rosh Hashana describes other random situations where an extra Adar could be declared as late as Adar I. As one rabbi put it, “The Sanhedrin had the power to determine whether we would be eating Matza or Hamentashen on the 15th of the month!”

If the roads were still very muddy from a rainy winter, a month would be added. The same was true if the cattle had not yet started mating. It was a sign that it was still winter.

A final reason for the leap year was that the grains were still brown, and had not shown any green. Spring was late that year.

It is certainly easier to have a set calendar. But it is fascinating to see how the principle that “The earthly court decrees, and the Heavenly court fulfills.” The role of the Rabbis in implementing the Torah should always be appreciated.

About the Author
Rabbi Cohen has been a Torah instructor at Machon Meir, Jerusalem, for over twenty years while also teaching a Talmud class in the Shtieblach of Old Katamon. Before coming to Israel, he was the founding rabbi of Young Israel of Century City, Los Angeles. He recently published a series of Hebrew language-learning apps, which are available at