Why Two Months of Adar?

Image: A Jewish calendar showing Adar Bet from 1927 through 1948. Public Domain.

If you have a Jewish calendar, you may have noticed that yesterday and today we celebrated Rosh Chodesh Adar Aleph, the first day of the month of Adar Aleph (Adar One). Next month is Adar Bet (Adar Two).  Why two months of Adar? Last year we had only one.

The Jewish calendar is both a lunar and a solar calendar. That means that it is aligned with both the moon and the sun. Our months are aligned with the moon – every Rosh Chodesh (new month) falls on a New Moon. The average lunar month is equal to 29 days, 12 hours, 44 minutes. The average solar year is equal to 365 days, 5 hours, 48 minutes, 45.51 seconds. If we stayed on a strictly lunar calendar, our holidays would slowly rotate around the seasons, as they do in the Islamic calendar. However, our holidays align to the seasons: Passover to springtime, for instance.

To keep the holidays in their proper seasons, the calendar adjusts periodically. One of the ways it does this is by adding a month of Adar whenever Passover strays too far from springtime. In ancient times, this was done by observations and adjustments announced by the Temple. Since the 4th century, we use a mathematic formula to determine when to add a month of Adar. If you are interested in the math, there are articles online that go into detail, but most Jews simply use a calendar.

But… why Adar? Why not Cheshvan or Av? Adar is the last month of the year (when you use the Biblical calendar, which counts Nisan as the first month.) So we are doubling the month at the end of the year.

However, it’s an interesting choice. Av and Adar have special associations, with Av as the “saddest/unluckiest month of the year” and Adar as the “happiest/luckiest month of the year,” drawing from the sacred days in them. In Av we remember the destruction of the Temple. Who wants to do that twice? But Purim falls during Adar, when we remember our deliverance from the evil plans of Haman. That’s worth remembering twice! (So you might well ask, do we celebrate Purim twice? See tomorrow’s post.)

The calendar is teaching us a subtle message: when we have the opportunity to dwell on something, choose joyful memories. It’s an extension of the commandment to “choose life” [Deuteronomy 30:19.]

I wish you joyful months of Adar!