Monthly Archives: March 2024

Leaping over the Moon (and the Sun)

Rabbi Gabriel Botnick focuses on a Jewish leap year

When I was a child, I wondered what it would be like to be born on 29 February. I figured it would feel rather special to have such a unique birthday. But then I worried it would mean you could
only celebrate your birthday every four years. One could settle most years for an annual ‘birthday’ party
on some random day, which didn’t seem fun to my young mind. Then the big concern would hit me: what
about birthday presents? Would you receive only a fraction of the gifts that your friends at school would get? And when your friends would all celebrate turning 16, would you still be just a mere four years old?!
As you can see, the concept of leap years used to send my developing brain into hyperdrive.

With this year being a leap year, this question recently – and unexpectedly – came back to my mind. As it so happens, not only is this a leap year on the secular calendar, but it’s also a leap year on the Hebrew calendar. But instead of adding just one extra day to the year, we get a whole extra month!

The secular Gregorian calendar is a ‘solar’ calendar, based on the time it takes the Earth to orbit the sun – approximately 365¼ days. A lunar calendar, on the other hand, is based on the cycle of the moon, which takes roughly 29½ days to fully wax and wane. A lunar year consists of 12 lunar cycles – or 354¹⁄3 days – which makes a lunar year rather shorter than a solar year, so holidays based on the moon’s cycle shift every year in relation to the secular calendar. For example, because the Islamic calendar is lunar, Ramadan can occur some years in the winter and other years in the summer.

So what about the Hebrew calendar? This is where things get confusing. While Judaism is indeed focused on the cycles of the moon, we actually follow a hybrid ‘lunisolar’ calendar. This means our months are based on the moon while our year is based on the sun. By combining these two systems, we are forced to find a way to resolve the 11-day disparity between the lunar and solar years. This is how we arrive at the idea of a leap month. In every 19-year cycle of the Hebrew calendar, there are seven leap years, during which we add an extra month, Adar I, in addition to the usual Adar, which becomes Adar II. During these leap years, the holidays can feel later than usual, as they might fall nearly a full secular month later than the prior year. This is why we may often find ourselves saying, ‘Rosh Hashanah is late this year’ or ‘Chanukah is early’.

Adar, of course, is the month in which Purim occurs. But in which Adar should we celebrate? The answer is Adar II. In fact, during a leap year, we must wait until this additional month to celebrate anything that occurs in Adar. Were you married in Adar? Lucky you – you get a whole extra month to find the perfect anniversary gift for your partner!

What happens to the Torah reading cycle in a leap year? Well, we still need to complete the full cycle by Simchat Torah, but now we have an extra month, which means we have to break up the Torah portions a bit differently. You may have noticed we sometimes read a ‘double’ portion, such as ‘Acharei Mot-Kedoshim’. During a leap year, these portions are split, meaning we read ‘Acharei Mot’ one week and ‘Kedoshim’ the next. And with 54 unique portions in the Torah, there are numerous ways we can merge or separate them so that the Hebrew calendar will always work out just right.

I realise all these numbers and variables might have your head spinning by now. But if you’re like me, then you too might think it’s pretty amazing how our tradition gives us so much to think about. So, this year, while the rest of the world gets to consider the implications of a single leap day, we get to ponder the wider complexities of a whole leap month. If only I had known about these things when I was a child, my imagination really could have run wild.