Asara B’Tevet / עֲשָׂרָה בְּטֵבֵת, the tenth day of the Hebrew month of Tevet, is a minor fast day in Judaism. The fast commemorates the siege of Jerusalem.
Although the Tenth of Tevet is an annual observance on the Hebrew calendar, the date can fall during December or January on the Gregorian calendar. In some Gregorian years, there is no observance of the fast. In other Gregorian years, the fast is observed twice.
For example, the Tenth of Tevet does not occur at all in during the Gregorian year 2024. The fast for Hebrew year 5785 will be observed in January 2025, and the Asara B’Tevet 5786 observance of the fast will be in occur in December 2025.
To illustrate further, consider the following 8-year table:
The Hebcal Torah Reading pages specify both the traditional full kriyah (reading the entire weekly Torah portion each Shabbat) and also a triennial cycle specified by the Conservative Movement in the United States.
“Many congregations pattern their weekly Torah reading cycle after a system similar to the one used in ancient Israel during the rabbinic period. In this system, the traditional parashiot are each divided into three shorter segments, and the whole Torah is completed once every three years. The system has both advantages and disadvantages, but its ability to shorten the length of Torah reading without sacrificing the complete reading of the Torah on a regular basis has made it the choice of some synagogues in the Conservative Movement.”
Although there is no formally specified triennial cycle for the Masorti movement in Israel, Hebcal began publishing a draft schedule in May 2023. Due to differences in the Torah readings schedule based on keeping only a single day of chag in Israel, the Diaspora triennial system does not work for a small number of parsha combinations that can occur in Israel.
In particular, Behar-Bechukotai and Matot-Masei occasionally occur with different 3-year patterns in Israel that never occur in the Diaspora. Rather than invent new aliyot divisions for Israel, we have adapted/reused the existing triennial variations used in the Diaspora.
Here is the draft schedule with some example years where the 3-year patterns occur.
Behar-Bechukotai
3-year pattern SSS (Separate in years 5774, 5775, 5776)
Hebcal would like to thank the following individuals and organizations that have privately reported security issues that affected the Hebcal.com website or online services and agreed to be listed.
To report an issue in Hebcal.com, please contact security@hebcal.com. Please allow a reasonable time (1-2 business days) for a response after reporting.
We have added the monthly cycle of studying Tehillim (Psalms) to our daily learning calendars.
Each day, we study a few chapters from the 150-chapter book of Psalms (Tehillim). The entire book is completed on the final day of each Hebrew month. On months with 29 days, the 30th portion is combined with the 29th portion.
For example, the reading for the 18th of Sivan, 5783 (Wednesday, 7 June 2023) is Psalms 88-89.
Hebcal can generate Candle-lighting & Havdalah times for Shabbat and holidays, and start and end times for fast days. Over 100,000 world cities are supported.
Candle-lighting times / הַדְלָקַת נֵרוֹת
By default, candle lighting time is 18 minutes before sundown (40 minutes for Jerusalem, 30 minutes for Haifa and Zikhron Ya’akov) on Erev Shabbat (Friday) and Erev Chag (Rosh Hashana, Yom Kippur, Sukkot, Shmini Atzeret, Simchat Torah, Pesach, Shavuot).
Hebcal gives an option to specify a different number of minutes before sunset if you don’t follow the 18-minute minhag (for example, some light candles 20 minutes before sundown).
Chanukah candle-lighting times are at bein hashmashos on weekdays. Rabbeinu Tam holds that bein hashmashos is a specific time between sunset and tzeit hakochavim. One opinion on how to calculate this time is that it is 13.5 minutes before tzies 7.083°. Chanukah candles are lit just before Shabbat candles on Friday, and immediately after Havdalah on Saturday night.
Havdalah / הַבְדָּלָה
Havdalah is calculated according to tzeit hakochavim / צֵאת הַכּוֹכָבִים, the point when 3 small stars are observable in the night sky with the naked eye (sun 8.5° below the horizon). This option is an excellent default for most places on the planet.
Hebcal also offers the option to use a fixed number of minutes past sundown. Typically one would enter 42 min for three medium-sized stars, 50 min for three small stars, 72 min for Rabbeinu Tam, or 0 to suppress Havdalah times.
Fast times
Minor fasts begin in the morning at alot haShachar / עֲלוֹת הַשַּׁחַר (solar depression 16.1 degrees) and conclude at tzeit for 3 medium sized stars (solar depression 7.083 degrees). Both start and end times are displayed for following minor fasts:
Tzom Gedaliah
Asara B’Tevet
Ta’anit Esther
Tzom Tammuz
Hebcal displays only a start time for Ta’anit Bechorot because customs vary about when to end the fast (often at a siyyum at the conclusion of morning services).
The fast of Tish’a B’Av begins at sunset and concludes at tzeit for 3 medium sized stars (solar depression 7.083 degrees).
Yom Kippur fast begins before sunset at regular candle-lighting time and concludes at Havdalah time. Hebcal doesn’t display “Fast begins” or “Fast ends” events for YK; instead, the fast start and end times are indicated with the regular “Candle lighting” and “Havdalah” event titles.
Sunset
According to the United States Naval Observatory,
Sunrise or sunset is defined to occur when the geometric zenith distance of center of the Sun is 90.8333 degrees. That is, the center of the Sun is geometrically 50 arcminutes below a horizontal plane. For an observer at sea level with a level, unobstructed horizon, under average atmospheric conditions, the upper limb of the Sun will then appear to be tangent to the horizon. The 50-arcminute geometric depression of the Sun’s center used for the computations is obtained by adding the average apparent radius of the Sun (16 arcminutes) to the average amount of atmospheric refraction at the horizon (34 arcminutes). [USNO]
If you ever have any doubts about Hebcal times, consult your local halachic authority.
If you select a location (or enter geographic coordinates) above the arctic circle or below the antarctic circle, the times are guaranteed to be wrong. The NOAA algorithm used to calculate the position of the sun is inaccurate at extreme northern and southern latitudes.
