The first and seventh days of Passover (Pesach), the first and eighth days of Tabernacles (Sukkos), the day of Pentecost (Shavuos), and the first day of the seventh month (New Year's Day -- Rosh ha-Shanah) are called festivals [lit. "good days"]. We are commanded to rest on them since they are called "sabbaths"¹; and we are forbidden to do any work on them except work that is necessary for preparing food, as it says "You shall not do any laborious work"²; "No work shall be done on them, but whatever is eaten by all... may be done for you".^3,a

Specifically, "slaughtering", "kneading" and "baking" are permitted on festivals as necessary for preparing food; "taking from one domain to another" (unostentatiously) and "burning" are permitted for any purpose (but kindling a new fire and extinguishing a fire are forbidden). On the other hand, "reaping", "threshing", "winnowing", "separating", "grinding" [except spices] and "sifting", as well as cheese-making, are forbidden on a festival since all such things can be done before the festival without depreciation or loss; in some situations, however, "separating", "grinding" and "sifting" are allowed if done in an unusual way as a reminder.^b "Hunting" is also forbidden. When an animal is slaughtered on a festival it can be skinned, but no special effort should be made to keep the skin whole or to preserve it.^c

When work is permitted for preparing food the food must be intended (at least in part) for consumption by Jews (as it says "for you"³) on the festival.^d When a festival occurs on Friday one may not prepare for the sabbath on the festival unless he has begun the preparation before the festival by setting aside some cooked food then [for the sabbath]; this food is called the "combination of cookings".^e Washing and anointing are like eating since they too are bodily needs; one can heat water on a festival to wash his face, hands and feet, but one cannot wash his whole body except in water heated before the festival.^f

Whatever is rabbinically forbidden on the sabbath (e.g., because it may lead to work) is forbidden on festivals unless it is necessary for preparing food. In addition, one may not handle anything that was not fit and specifically intended, before the festival began, for consumption on the festival.^g

We are commanded to honor the festivals and make them enjoyable like the sabbath; and we also recite benedictions at their beginning and end. We should be joyful on the festivals (as well as on the intermediate days of Pesach and Sukkos; see below) and we must not mourn or fast on them, as it says "And you shall rejoice on your festival".⁴ Celebrations such as weddings that are not related to the festival must not be held.^h

b) The Second and Intermediate Days

Outside the land of Israel it is customary to celebrate each of these festivals for two days; and Rosh ha-Shanah is celebrated for two days even in the land of Israel. Even though the second day is only a rabbinical institution, everything forbidden on the first day is also forbidden on the second day except for care of the dead.ⁱ

Some types of work are also forbidden on the days between the first and seventh day of Pesach and between the first and eighth day of Sukkos. (Similar regulations apply on the afternoon preceding Pesach.^j) In general, any work that does not require great effort and that is needed then or will lead to great loss if it is not done then may be done on those days, but not ostentatiously.^k One must not deliberately defer work until then; in particular cutting the hair and washing clothes are forbidden since one may come to defer them and not prepare himself properly for the first day of the festival.^l

Sources:
1. Lev. 23:24,39	a. 1:1-2
2. Lev. 23:7-8,21,25,35-36; Num. 28:18,25,26; 29:1,12,35	b. 1:4,7; 3:12 ff; 4:1-2; 5:lff.
3. Ex. 12:16	c. 2:7; 3:4-6
4. Deut. 16:14	d. 1:9,13
	e. 6:1
	f. 1:16
	g. 1:17-18; see 4:10
	h. 6:16-17; 7:16; Shabbos 29:18
	i. 1:21-22
	j. 8:18
	k. 6:22; 7:1-2,6,9
	l. 7:4,17