Question 1

How do you calculate a yahrzeit date?

Accepted Answer

Convert the Gregorian date of death to the Hebrew calendar date using the lunisolar conversion algorithm. If the death occurred after sunset, move the Hebrew date forward by one day (since Hebrew days begin at sunset, not midnight). The yahrzeit is then observed on that same Hebrew date every subsequent year. Because the Hebrew year is ~11 days shorter than the Gregorian year (354 vs 365 days), the Gregorian date shifts each year and requires recalculation.

Question 2

When do you light the yahrzeit candle?

Accepted Answer

Light the yahrzeit candle at sunset on the evening before the yahrzeit date. For example, if the yahrzeit falls on Wednesday, light the candle on Tuesday at sunset. The candle should be a 24-hour memorial candle (ner neshamah) that burns through the entire yahrzeit day. These candles are widely available at grocery stores, Judaica shops, and online. Some families light a second candle at the grave site if they visit the cemetery.

Question 3

What is the difference between yahrzeit and yizkor?

Accepted Answer

Yahrzeit is the annual anniversary of an individual's death, observed on the specific Hebrew date of passing. Yizkor is a communal memorial prayer service held four times per year on fixed holidays: Yom Kippur, Shemini Atzeret (8th day of Sukkot), the last day of Passover, and the second day of Shavuot. During yizkor, the congregation collectively remembers all deceased loved ones. Someone can observe both — yahrzeit is personal and date-specific, while yizkor is communal and calendar-fixed.

Question 4

Does the after-sunset option matter for yahrzeit calculation?

Accepted Answer

Yes, critically. In the Jewish calendar, a new day begins at sunset (not midnight). If someone passed away on January 15th after sunset, the Hebrew date is actually the 16th of January's Hebrew equivalent. This one-day shift affects every future yahrzeit date permanently. If you're unsure whether the death occurred before or after sunset, consult the death certificate's time of death and compare it to the sunset time for that location and date.

Question 5

What happens to yahrzeit when there are two Adars in a leap year?

Accepted Answer

Hebrew leap years add an extra month, Adar I (30 days), before the regular Adar, which becomes Adar II (29 days). The standard Ashkenazi practice (per the Rema) is: if the death occurred in Adar of a regular year, observe the yahrzeit in Adar II of a leap year. If the death was in Adar I of a leap year, observe in Adar I when possible, otherwise in the single Adar. Some Sephardic authorities place the regular-year Adar yahrzeit in Adar I instead. Consult your rabbi for your community's practice.

Question 6

Is the first yahrzeit observed one year after death?

Accepted Answer

Yes. The first yahrzeit falls on the first anniversary according to the Hebrew calendar — typically 12 Hebrew months after the death (or 13 months if a Hebrew leap year intervenes). This is different from the mourning periods: shiva (7 days), shloshim (30 days), and the year of mourning (for parents). The first yahrzeit may fall on a different Gregorian date than the original death date because Hebrew and Gregorian years are different lengths.

Question 7

What prayers are said on a yahrzeit?

Accepted Answer

The primary prayer is the Mourner's Kaddish, recited at all three daily synagogue services (Shacharit, Mincha, and Ma'ariv). Additional prayers and practices include: El Malei Rachamim (memorial prayer asking for the soul's peaceful rest), Psalms 23 ("The Lord is my shepherd") and 121 ("I lift my eyes to the mountains"), studying Mishnah (particularly chapters whose letters spell the deceased's Hebrew name), and some recite the entire book of Psalms.

Question 8

Can I observe yahrzeit if I don't know the exact date of death?

Accepted Answer

Yes — consult a rabbi for guidance on choosing a date. Common approaches include: using the date of burial instead, using the date the death was discovered, selecting the closest known date and observing it consistently, or checking the gravestone (matzevah) which often has the Hebrew date inscribed. In cases of Holocaust victims where dates are unknown, some communities observe yahrzeit on Yom HaShoah or the 10th of Tevet (a designated day for unknown yahrzeits).

Question 9

Why does the yahrzeit date change on the Gregorian calendar each year?

Accepted Answer

The Hebrew calendar is lunisolar: months follow the moon's 29.5-day cycle, making a regular year ~354 days (11 days shorter than the 365-day Gregorian year). In 7 out of every 19 years, a leap month is added, creating a ~384-day year. This means a Hebrew date drifts roughly 11 days earlier on the Gregorian calendar each regular year, then jumps about 19 days later when a Hebrew leap year occurs, keeping the cycle anchored to the seasons over the 19-year Metonic cycle.

Question 10

What if the yahrzeit falls on Shabbat or a Jewish holiday?

Accepted Answer

The yahrzeit is still observed on its correct date regardless of whether it falls on Shabbat or a holiday. The candle is lit before Shabbat candle-lighting time (since you cannot kindle fire on Shabbat). Kaddish is recited at services as usual. If the yahrzeit falls on Yom Kippur, the candle serves double duty as both the yahrzeit candle and the Yom Kippur memorial candle. On holidays when Yizkor is recited, the yahrzeit observance and yizkor complement each other.

Question 11

Do all Jewish denominations observe yahrzeit the same way?

Accepted Answer

The core observance — lighting a memorial candle and reciting Kaddish on the Hebrew death anniversary — is universal across Orthodox, Conservative, and Reform Judaism. Differences arise in specifics: some Sephardic communities follow different Adar leap-year rules; Reform communities may accept observance on the Gregorian anniversary; Chabad emphasizes Torah study and leading prayer services; and some communities have the custom of fasting on a parent's yahrzeit. The emotional and spiritual intent is the same across all traditions.

Question 12

How do Cheshvan and Kislev variable days affect yahrzeit?

Accepted Answer

The months of Cheshvan and Kislev can each have either 29 or 30 days, depending on the year type: a deficient (chaser) year has both at 29 days, a regular (kesidrah) year has Cheshvan 29 and Kislev 30, and a complete (shalem) year has both at 30 days. If a death occurred on the 30th of Cheshvan or Kislev, and a future year's version of that month has only 29 days, the yahrzeit is observed on the 29th (the last day of the month).

Situation	Yahrzeit Observed In	Note
Death in Adar (non-leap year)	Adar II in leap years	Ashkenazi practice (Rema). Some Sephardic hold Adar I.
Death in Adar I (leap year)	Adar I if leap; Adar if not	Follows the specific Adar of death when possible.
Death in Adar II (leap year)	Adar II if leap; Adar if not	Adar II is the "real" Adar — maps to single Adar in regular years.
Death on 30 Cheshvan / 30 Kislev	29th if month is short that year	These months vary (29 or 30 days) by year type.

Month	Days	Season	Notable
Tishrei	30	Sep–Oct	Rosh Hashanah, Yom Kippur, Sukkot
Cheshvan	29 or 30	Oct–Nov	Variable length (chaser/malei)
Kislev	29 or 30	Nov–Dec	Variable length; Hanukkah begins 25 Kislev
Tevet	29	Dec–Jan	Fast of 10 Tevet
Shevat	30	Jan–Feb	Tu BiShvat (15 Shevat)
Adar	29	Feb–Mar	Purim (14 Adar); in leap years: Adar I (30) + Adar II (29)
Nisan	30	Mar–Apr	Passover begins 15 Nisan
Iyyar	29	Apr–May	Lag BaOmer (18 Iyyar)
Sivan	30	May–Jun	Shavuot (6 Sivan)
Tammuz	29	Jun–Jul	Fast of 17 Tammuz
Av	30	Jul–Aug	Tisha B'Av (9 Av)
Elul	29	Aug–Sep	Month of repentance before Rosh Hashanah

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Complete Yahrzeit Observance Guide

Hebrew Calendar Month Reference

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