A Comprehensive Guide to the Laws of Rosh Chodesh

Rosh Chodesh Meals

1. It is a mitzvah to cook an extra dish to serve in honor of Rosh Chodesh, primarily during the daytime meal. If one enhances the daytime meal with a special food or cooked dish, there is no need to supplement the evening meal.

2. The added effort and expense of enhancing Rosh Chodesh meals is considered praiseworthy, as long as our intention is to honor Rosh Chodesh.

3. In the Birkat Hamazon, we add the Ya'aleh veYavo prayer to the third blessing. If a person forgets, he is not obligated to repeat the Birkat Hamazon, as it is not obligatory to wash for bread at a Rosh Chodesh meal. 

Maariv of Rosh Chodesh

1. In the Amidah recited on Rosh Chodesh, one adds the Ya'aleh veYavo prayer to the brachah of "Retzei."

2. The custom is for the shamash to remind those praying to recite the Ya'aleh veYavo prayer before the Amidah. During Maariv, this is accomplished by clapping on the bimah.

3. If one forgets to add Ya'aleh veYavo in the Maariv Amidah, there is no need to (and one may not) repeat the prayer, as the new month is not sanctified at night. This applies to both days of Rosh Chodesh in a month where Rosh Chodesh is two days. Even if one realizes he forgot to add Ya'aleh veYavo after saying, "Baruch Atah Hashem" and before ending the "Retzei" brachah, he does not add "lamdeni chukechah" in order to be able to insert Ya'aleh veYavo, but completes the brachah without the insertion.

4. If one is praying the Maariv Amidah and the chazan has begun Kaddish, one should not skip Ya'aleh veYavo in order to end the Amidah quickly and answer Kaddish.

Shacharit and Minchah of Rosh Chodesh

1. The shamash reminds those praying to recite the Ya'aleh veYavo prayer before the Amidah — before Shacharit, this is accomplished by clapping on the bimah; before Minchah, the shamash announces: "Ya'aleh veYavo!"

2. If a person completes the brachah of "Retzei" and begins the next brachah ("Modim") and then realizes he forgot to recite Ya'aleh veYavo, he must return to the beginning of "Retzei," as reciting it without Ya'aleh veYavo is like omitting the entire brachah. Merely adding Ya'aleh veYavo once the brachah of "Retzei" has been completed accomplishes nothing.

3. If a person finishes the entire Amidah and only then realizes that he forgot to recite Ya'aleh veYavo, he must repeat the Amidah for either Shacharit or Minchah. He should have in mind that if he is not genuinely obligated to repeat the prayer, Hashem should consider his prayer a voluntary offering. The same applies if he finishes the Amidah and cannot recall whether he recited Ya'aleh veYavo.

4. If a person finishes the Mussaf prayer and only then realizes that he forgot to recite Ya'aleh veYavo in Shacharit, he must repeat the Shacharit Amidah, preferably while wearing tefillin.

5. If a person forgets Ya'aleh veYavo in Minchah and realizes this only in the evening, he may offer an extra Amidah prayer instead of the Minchah prayer but should consider the prayer a voluntary offering. If it is still Rosh Chodesh (i.e., it was a two-day Rosh Chodesh) then he will recite Ya'aleh veYavo in both Maariv Amidah prayers. If at Maariv it is no longer Rosh Chodesh, he will not recite Ya'aleh veYavo in either Amidah prayer.

6. If a person is in the middle of the Amidah prayer and is unsure of what he should say and when, he may walk over to a Siddur or halachah sefer to find the information he needs.

Reciting Hallel on Rosh Chodesh

1. On Rosh Chodesh, we recite Half-Hallel with two chapters omitted, as is indicated in the Siddur. If one mistakenly recites the entire Hallel, there is no need to repeat the entire prayer. However, if one changes the order of the chapters, he must repeat the prayer.

2. Hallel should be recited calmly and with joy. It should not be rushed; neither should the prayer be unusually prolonged, as Rosh Chodesh is not a day when we are forbidden to work.

3. Ashkenazim recite the brachah, "Who commanded us to recite Hallel" both on Yom Tov and on Rosh Chodesh. Sephardim in Eretz Yisrael do not recite the brachah on Rosh Chodesh and should not even answer Amen if they hear another person reciting the brachah. Outside the Land of Israel one should consult one's rabbi.

4. If a Sephardi leads the Rosh Chodesh prayers in an Ashkenazi synagogue in Eretz Yisrael, someone else should recite the brachah before Hallel.

5. One may not interrupt the Hallel prayers in any way, such as by speaking. However, if one hears a person reciting a brachah, one may answer Amen.

6. Hallel should ideally be recited with a minyan. If one arrives late in synagogue and the congregation is about to begin Hallel or has already begun, he should recite Hallel together with the congregation and only then begin his prayers.

7. Hallel should be recited standing, unless one is ill or elderly in which cases one may remain seated.

8. Women are exempt from reciting Hallel but they may recite the prayer if they wish. They should not recite the brachah beforehand (except for on Pesach, when the brachah is recited, even by women).

9. After Hallel, the verse: "And Abraham was old, advanced in days" is recited.