Take the 2-minute tour ×
Mi Yodeya is a question and answer site for those who base their lives on Jewish law and tradition and anyone interested in learning more. It's 100% free, no registration required.

For those outside of Israel the requirement is for two days of yom tov (and sometimes Rosh Chodesh), originally due to uncertainty and now due to tradition. But we don't do this for all holidays even though they involve time-bound mitzvot:

  • Yom Kippur: it would be impractical to observe for two days; is that the reason or is it coincidence?

  • Chanukah: is the 25th of the month late enough that we are certain of the date?

  • Purim: I have no guess here

Is there a unifying reason for when we do and don't add the second day, and if so what is it? Or is it on case-by-case basis, and if so what are the reasons for these three cases?

share|improve this question

3 Answers 3

up vote 9 down vote accepted

You are right as to the reason why we don't have two days of Yom Kippur is because it is dangerous and we don't decree on people decrees that they can't handle.

As to the other two, see 9 Days of Chanukah?

share|improve this answer

It's not necessary to keep 2 days for a holiday that is d'rabanan and that has no issur melacha.

share|improve this answer

Yom Kippur -- they realized that most people can't handle a 48-hr fast, so they didn't enact it.

Purim and Chanukah -- came much later in history, and aren't "no-work" holidays. Never mind they're entirely of post-Mosaic origins, which means we're more lenient with them in cases of doubt.

share|improve this answer
Chanuka and Purim were instituted when they had Sfeika dyoma. Sfaika dyoma ended after the Mishna, while purim/chanuka is pre-churban (purim is pre-second Beis Hamikdash). Also do you have a source that Rabinic Holidays do not have sfeika dyoma issues) –  Shmuel Brin Oct 9 '11 at 6:51

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.