Why do Jewish holidays change their date

Question

Let’s say rosh Hashanah. It varies it’s date every year, but if the Jewish calendar is a fixed amount of days, wouldn’t it be earlier and earlier or later and later every year?

In: 4

Answer 1

The dates don’t change. For example, Rosh Hashanah always begins on the first of Tishrei. But this is on the Jewish calendar which isn’t aligned with the Gregorian calendar, which is why it is on different dates with respect to the Gregorian calendar.