Rabbi Zachary Hepner
Jewish Life Cycle Calculator
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Jewish Life Cycle Calculator
Enter a child’s Gregorian birthday to find their Hebrew birth date,
upsherin (age 3, for boys), Zeved HaBat / Simchat Bat baby naming (girls),
and bar or bat mitzvah date, along with the parashat hashavua their bar or
bat mitzvah falls on.
The rules this calculator follows
| Hebrew birth date | Converted from the Gregorian date of birth entered above. |
|---|---|
| Brit Milah / Bris Mila (boys) | Shown as the 8th Hebrew day after birth. The bris may not be done prior to this date, and many brisses are postponed past it for health or other reasons – see the note shown with the date. |
| Upsherin (boys) | The child’s first haircut, traditionally held on his third Hebrew birthday. This is a widely observed custom, though not a halachic obligation. While the practice has long been a cherished Yemenite (Teimani) custom, it has become increasingly popular throughout the broader mainstream Jewish community in recent generations. |
| Upsherin during the Omer | If the 3rd Hebrew birthday falls on any of the first 33 days of the Omer (16 Nisan through 18 Iyar), the upsherin is postponed to Lag BaOmer. |
| Upsherin on Shabbat / Yom Tov | Upsherin is never held on Shabbat or a major Yom Tov. If the 3rd Hebrew birthday (or the Lag BaOmer date it was moved to) falls on one, it’s postponed to the next available day. |
| Zeved HaBat / Simchat Bat (girls) | Shown as the 15th Hebrew day after birth. There’s no fixed halachic date for this celebration – see the note below. |
| Hanachat Tefillin (boys) | The beginning of wearing tefillin, traditionally one to two months before the Bar Mitzvah, allowing the boy to become familiar with the mitzvah before he becomes fully obligated at age 13 (according to his Hebrew birthday). Some communities begin 30 days before the Bar Mitzvah, while others start two or three months beforehand; this calculator shows the 30-day mark. The first time tefillin are worn is often marked by a small family celebration. |
| Bar mitzvah (boys) | The child’s 13th Hebrew birthday. |
| Bat mitzvah (girls) | The child’s 12th Hebrew birthday. |
| Hadlakat Neirot (girls) | Shown as the first Friday (Erev Shabbat) or Erev Yom Tov on or after 30 days before the Bat Mitzvah. Many Jewish women only begin lighting Shabbat candles when they marry; the custom among Chabad women is to begin at their Bat Mitzvah. Hadlakat neirot is always done during the daytime, traditionally 18 minutes before sunset, and is never done after the sun has set. |
| Adar birthdays | If a child is born during Adar, their bar or bat mitzvah date depends on whether the Hebrew year they turn 13 (or 12) is a leap year, which has two months of Adar. This calculator follows the generally accepted rule: a child born in the single Adar of a regular year becomes bar or bat mitzvah in Adar Sheni (Adar II) if their milestone year is a leap year. A child born in Adar Rishon (Adar I) of a leap year stays with Adar Rishon if their milestone year is also a leap year, and a child born in Adar Sheni (Adar II) stays with Adar Sheni. As with any Adar question, confirm with your rabbi if you’d like a personal ruling. |
| Parashat Hashavua | The Torah portion read on the Shabbat that falls during the Hebrew week (Sunday through Saturday) containing the bar or bat mitzvah date. |
Welcoming a Baby Girl: Zeved HaBat / Simchat Bat
Unlike a Brit Milah, which has a specifically prescribed day in Jewish
law, there is no fixed halachic date for a Zeved HaBat or Simchat Bat.
Throughout Jewish history, families have observed this joyous occasion at
a variety of times, reflecting the customs of their communities and their
own family’s circumstances.
In many Sephardi and Mizrahi communities, the ceremony is traditionally
held within the first few weeks after birth, often when the mother is
able to return to the synagogue. In some communities, the celebration
takes place on the first Shabbat after the baby’s birth, while others
schedule it at another convenient time during the first month.
Among Ashkenazi families, the baby’s Hebrew name is often announced at
the first Torah reading following the birth, commonly on the first
Shabbat that the father is called to the Torah. A Simchat Bat celebration
may then be held that same Shabbat or at another time in the weeks that
follow.
The significance of choosing to celebrate on the 15th day after birth
is based on Leviticus 12:5, where the Torah describes the completion of
the fourteen-day period following the birth of a daughter. On the
fifteenth day, the post-partum mother would have completed this initial
stage and subsequently immersed herself in the mikvah. During the Temple
period, the fifteenth day marked a significant milestone in the life
cycle and may also be an appropriate and meaningful time to celebrate the
arrival and naming of a baby girl.
Today, families enjoy great flexibility in planning this special
occasion. Some families traditionally choose to have the Hebrew naming
take place in the synagogue during a Torah service, emphasizing the
communal and liturgical aspect of welcoming their daughter into the
Jewish people. Others prefer to bestow the Hebrew name during the
celebration itself, allowing family and friends to share in this
intimate and joyous moment. Either approach beautifully honors the birth
of a daughter while reflecting the rich diversity of Jewish tradition.
This tool provides general information based on commonly followed customs
and calendar calculations, not a personal halachic ruling. Please confirm
your specific dates with Rabbi Hepner or your rabbi.
Jewish calendar dates and parasha data from Hebcal.com.