Why the date moves every year
Twelve Hebrew months add up to about 354 days, so in most years your Hebrew birthday arrives about 11 days earlier on the civil calendar than the year before. Every two or three years a leap month pushes it about 19 days later. Over a 19-year cycle the two calendars line up, which is why the dates often coincide around ages 19, 38 and 57.
Hebrew birthday questions
What is a Hebrew birthday?
It is your birthday on the Hebrew calendar: the Hebrew day and month you were born. Because the Hebrew year has a different length from the civil year, it falls on a different civil date most years.
How do people mark a Hebrew birthday?
Common customs include an aliyah to the Torah on the Shabbat before, extra tzedakah, taking on a new mitzvah, and a festive meal. It is also the date of a bar or bat mitzvah.
I was born at night. Which date is mine?
If you were born after sunset, your Hebrew birthday is the next Hebrew date. Choose After sunset.
I was born on 30 Cheshvan or 30 Kislev. What about years without that day?
In years when the month has only 29 days, the birthday is kept on the 1st of the following month.