Our Gregorian calendar adds a leap day every four years, except during century years not evenly divisible by 400. We do this to keep our seasonal years aligned with the astronomical year of approximately 365.24219 days. Without this leap day, we might be shoveling snow on Independence Day as often as we sit on the beach.
The Jewish calendar is tied to the lunar cycle, with 12 lunar months not quite equaling an astronomical year. So, in order to keep Jewish holidays in their season, our rabbis added the leap month that occurs seven times every 19 years.
While the Gregorian leap day has nearly no significance on our lives, the Jewish leap month is the direct cause of the “early/late this year” phenomenon of our Jewish holidays. Rosh Hashanah always falls on the first two days of the Hebrew month of Tishrei, and to the rabbis’ point, always during its season, but the holiday can fall anywhere between September 5 and October 5 on the Gregorian calendar, depending on where we are in the 19-year Jewish cycle.
“Thanks Rob. Why are you telling us about this today?”
We just added a leap month and so all Jewish holidays starting with this past Purim will be “late” for a little while, including Yom HaZikaron, Israel’s Memorial Day. This weekend, we will be commemorating America’s Memorial Day fresh off the heels of Israel’s very difficult Memorial Day, which we observed as a community only a week and a half ago. With Israel’s losses fresh in our minds, we remember our own country’s fallen and thank them for their service and sacrifice. May all their memories be for a blessing.