Nishmat's Women’s Health and HalachaIn memory of Chaya Mirel bat R' Avraham

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Keeping days 30 & 31 as onah beinonit

10 June, 2005


Since I got married, I have always observed the days 30 and 31 as the onah beinonit, but recently heard that this is not halachically required. Could you advise me on this question?


There are a variety of customs with respect to the Onah Beinonit

Most authorities hold that the onah beinonit falls on the thirtieth day from the beginning of a woman's last menstrual period. The first day of her period is day one, and the onah beinonit is day thirty.  Some authorities maintain that the onah beinonit falls on the thirty-first day from the beginning of a woman's last period. Therefore, some women have the custom to observe both the thirtieth and thirty-first days as onot perishah.  Additionally, some women observe onah beinonit for a full 24 hours, from sunset to sunset, of whatever Hebrew date the onah beinonit falls on.

Since this is a matter of custom, we recommend that you or your husband contact your rabbi for his position on this issue.  Generally, a hatarat nedarim would be required for such a change, as changing this custom is not automatically permitted.

This internet service does not preclude, override or replace the psak of any rabbinical authority. It is the responsibility of the questioner to inform us of any previous consultation or ruling. As even slight variation in circumstances may have Halachic consequences, views expressed concerning one case may not be applied to other, seemingly similar cases. All health and health-related information contained within Nishmat's Women's Health & Halacha Web site is intended to be general in nature and should not be used as a substitute for consulting with your health care professional. The advice is intended to offer a basis for individuals to discuss their medical condition with their health care provider but not individual advice. Although every effort is made to ensure that the material within Nishmat's Women's Health & Halacha Web site is accurate and timely, it is provided for the convenience of the Web site user but should not be considered official. Advice for actual medical practice should be obtained from a licensed health care professional.

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