Ask the Rabbi

Ask the Rabbi December 2023

Rabbi Carla Freedman

December 2023 Question

I know that sometimes our holidays and holy days are “early” or “late”…but I have never understood why that happens. Can you please explain?

December 2023 Answer

I’ll try!

The first thing to understand is that the secular calendar…the 12 month, January-December calendar we all use all the time…is a solar calendar. It’s based on the time it takes for the planet Earth to go around the sun…365 days. The Jewish calendar is lunar…it is based on the cycles of the moon. A complete cycle…a “moonth” is about 28 days. A full year of 12 “moonths” equals 336 days, 29 days short of the full solar year’s 365 days.

Because of that difference, the events we think of as seasonal, like Chanukah, Pesach, etc. would occur on the same date of the secular calendar, but the Jewish date would gradually slip out of synch.

This is best illustrated by the Muslim calendar, which is also a lunar calendar. Their month of Ramadan, during which Muslims don’t eat or drink during daylight hours, can occur at any season of the year (that Ramadan fast is much easier in December than July). The
Muslim calendar does not include a solar correction, which explains why Ramadan can occur at any season.

Because the Torah refers to Pesach as the festival of the spring, the Jewish calendar must be tied to the seasons. This is achieved by providing a solar correction to the lunar calendar. The sage Hillel II established the calendar as we know it, around the year 360 CE; he instituted a 19-year cycle, during which, 7 times, there is an additional “moonth”
added to the year. This is similar to the addition of February 29th, every 4 years, on the secular calendar (but a lot more complicated to work out!). That month is Adar II. It is inserted before Nisan, the month when Pesach occurs, to move Pesach from late winter clearly into spring.

When that happens, all the holy days and holidays that occur thereafter will be about a month later than they were the previous year. The next year, the gap will shorten, and soon it will be necessary to introduce the correction again.

This year, 5784, is a leap year on the Jewish calendar, and we will see it in the spring, when Pesach begins on the evening of April 22 (or the 15th of Nisan). And you’ll know why, this year.

There’s a lot more to the Jewish calendar and its flexibility, but this explanation covers the question of “early” or “late”.

And of course, the Jewish holy days and holidays are never early or late…they always occur on the same date on the Jewish calendar…on time every year.

But that, of course, is a matter of perspective…

Please send your questions directly to me at: