top of page

Rabbi’s Update 9/1/2023

Dear Friends:

Jewish holidays are always either “early” or “late". When was the last time you heard someone say "Rosh Hashanah is right on time this year?" Two years ago the first night of Rosh Hashanah was on Labor Day. Next year, Rosh Hashanah starts on October 2.

Today, of course, we have tools that allow us to know when a particular holiday will fall, in any particular year. If you want to know when Rosh Hashanah was in 1492, or will be in the year 2525, you can easily find out. This is possible because of the many Jewish calendar computer programs and websites. But none of this could happen if we didn't have a fixed calendar. In ancient days, however, the calendar was not fixed and had to be determined every year.

The reason that holidays fall "late" or "early" has to do with the hybrid nature of the Jewish calendar. Our months, of course, are lunar. Rosh Chodesh, the first day of the month, is the new moon, while most holidays fall on the 14th or 15th of the month, coinciding with a full moon. The problem is that twelve lunar months make a year of only 354 days, which would have the holidays creeping forward so that eventually Passover would be in the winter rather than the spring and the High Holidays in the summer rather than the fall.

The Islamic calendar is purely lunar and this is not a problem for them, since their holidays aren't tied to any specific season. But having spent some time in Australia where the seasons are reversed, it felt very strange to be building a Sukkah in the spring. Many of our holidays are tied to a certain season and so a method was developed to correct for the shorter lunar year vis-a-vis the solar one. Every so often, an extra month is added. This explains why very"early" High Holidays are usually followed by a very "late" Passover -- an extra month will be added between the two. For almost two thousand years these extra months have been added on a cycle of seven extra months every nineteen years. The addition of an extra month is known as intercalation.

When the Holy Temple stood in Jerusalem, however, the system was different. There was no fixed calendar and every year a group of scholars would convene to determine whether to intercalate that year or not.

One of the more interesting provisions in Jewish law, to my mind, is the fact that the High Priest was not allowed to participate in the decision about intercalation. Why is this? Because during the course of the Yom Kippur service, the High Priest had to immerse himself five separate times in an outdoor mikveh (ritual bath) on the Temple Mount. The later in the year Yom Kippur fell, the colder it was likely to be, and Jerusalem in early October, when Yom Kippur would fall in an intercalated year, can potentially be pretty chilly. Therefore the High Priest had a vested interest in not intercalating the year -- his mikveh immersions would take place in warmer weather and be more comfortable. In order that the High Priest not be tempted to put his own interests over those of the nation as a whole, he was not allowed to participate in the decision about intercalation. Jewish law does not allow a judge to participate in making a judgment about something in which the judge has a personal stake.

As a reminder, I am having drop-in hours on Thursday afternoon from 2 to 4 at the shul. You do not need to make an appointment -- that would negate the whole point of drop-in hours -- but I’d urge you to check and make sure I am there regardless as sometimes there are unavoidable pastoral or other emergencies which might take me away from the building.

As always, if I can do anything for you or you need to talk, please contact me at or 301-977-0768 rather than through the synagogue office. I am happy to meet you at the synagogue by appointment. I have been spending more time in the synagogue recently but if you want to speak with me it’s best to make an appointment rather than assuming I will be there when you stop by.

Shabbat Shalom,

Rabbi Charles L. Arian

13 views0 comments

Recent Posts

See All


bottom of page