Jewish Holidays 2024 Rosh Hashanah. However, many reform congregations observe. The jewish calendar is both solar and lunar, consisting of 12 months of either 29 or 30 days.

The jewish year (5784, 5785, etc.) begins on rosh hashanah and ends just before the following rosh hashanah. Rosh hashanah is observed on the first two days of the jewish new year, tishrei 1 and 2, beginning at sundown on the eve of tishrei 1.