Kiddush Levana (also Kiddush Levanah or Birkat HaLevana, the Sanctification of the Moon) is a blessing said once a month while the moon is growing. It’s usually recited outdoors at night when the moon is visible, and many people wait until Saturday night after Shabbat. Wikipedia has a good overview.
Kiddush Levana can only be said during part of the month. The window opens a few days after the molad (the calculated new moon) and closes around the middle of the month, once the moon starts to shrink. Opinions differ on both ends:
- Earliest: 3 days after the molad (the common practice) or 7 days after (following the Shulchan Aruch and Kabbalistic sources).
- Latest: halfway between one molad and the next (the Maharil, brought by the Rema), which is 14 days, 18 hours and 22 minutes after the molad. Others hold a full 15 days after the molad (the Shulchan Aruch).
The OU’s Halacha Yomis covers both questions: the earliest time and the latest time.
The molad happens at the same moment everywhere in the world, so the deadline lands at a different local time in each city. In one month the last night might run until 3am in Tel Aviv, while in San Francisco it already ended the evening before.
How Hebcal calculates it
Hebcal now adds a monthly Latest Kiddush Levana event, calculated for your location:
- We use the Maharil’s opinion (halfway between moladot). It’s the earlier of the two common opinions, so the event won’t send you past the deadline under either one.
- If the deadline falls during the day, we move it back to dawn (alot hashachar) that morning. That’s the end of the last night on which you can still say it.
- If the deadline falls on Shabbat or a Yom Tov, we move it back to candle-lighting time before Shabbat or Yom Tov, so you know to say it on an earlier night.
- The event description lists all four times: earliest after 3 days and after 7 days, and latest by the Maharil and after 15 days. You can follow whichever opinion your community does.
For example, in New York the last chance for the month of Cheshvan is Sunday, October 25, 2026 until 9:44pm. For Kislev, the Maharil’s time is Tuesday, November 24 at 9:28am, which is during the day. The calendar therefore shows 5:27am, meaning Monday night is the last night.
As always, ask your rabbi about your community’s practice.
How to add it to your calendar
- Go to hebcal.com/hebcal and enter your city or ZIP code under Candle-lighting & Fast times. Make sure the Rosh Chodesh box is checked. It’s on by default, but you need both.
- Click Create Calendar.
That’s it. Latest Kiddush Levana appears once a month on your calendar. If you download or subscribe to the calendar in Google Calendar, Apple Calendar or Outlook, each event’s description also includes the earliest times.
Already subscribed to a Hebcal calendar with candle-lighting times and Rosh Chodesh? The new events will appear on their own the next time your calendar app refreshes.
Thanks to the Hebcal user who suggested this feature on our feedback forum!
