Although it is not recorded in the Talmud, an ancient tradition advises bride and groom to fast on the day of their wedding. (This applies both to those who are marrying for the first time and to those who are remarrying.) They fast from daybreak until after the chuppah, eating their first meal during their yichud seclusion at the end of the ceremony.

Two reasons are advanced for fasting. First, tradition records that the sins of the bride and groom are forgiven on their wedding day. Because it is a day of forgiveness, it is considered a day of spiritual inventory and of repentance, akin to Yom Kippur—as represented by the fasting, the wearing of white, and the recitation of the confession at prayers (vidui and al chet).

The second reason is more practical, and halakhically more functional. The Sages sought to avoid the drinking of liquor before the wedding, as guests and relatives toast the future—it is a long way from stag nights and prenuptial bacchanalias, customary the world over, to the fast day of the traditional Jew. Unlike a Yom Kippur-type fast, which would require observance until nightfall, the wedding fast lasts only until after the chuppah, even if it takes place in the afternoon. It is not necessary to "make-up" the fast (hashlamah) on another day, in the event of a midday chuppah. Even though it is a personal fast, there need be no formal acceptance or vow to fast. If the chuppah is delayed beyond nightfall, and fasting becomes difficult, bride and groom may eat, but not drink intoxicating beverages. If even during the day the fast becomes too burdensome, they should discontinue it rather than arrive ill at the chuppah.

Days of No Fasting

The following are days, as recorded in the Talmud, on which one does not fast. To do so would contravene the sense of public joyousness. When one does not fast, one should nonetheless not eat excessively, and surely not drink intoxicating liquids.

1. Rosh Chodesh, except Rosh Chodesh Nissan, when one should fast.

2. Issru Chag, the day following the final days of Passover, Shavuot, and Sukkot.

3. Hanukkah

4. Purim, both Purim and Shushan Purim (the day following)

5. Fifteenth day of Av

6. Fifteenth day of Shevat

One does fast on:

1. Lag Ba-Omer

2. The days between Yom Kippur and Sukkot

3. The days between Rosh Chodesh Sivan and Shavuot

4. All days of Nissan