Rosh Hodesh

In Judaism, Rosh Hodesh is a minor festival celebrated at the beginning of each month in the Hebrew calendar, signaled by the emergence of a new moon (Hebrew: ראש חודש; trans. Beginning of the Month; lit. Head of the Month). Depending on whether the preceding month had 29 or 30 days, Rosh Hodesh is observed for either one or two days.

Given that Judaism follows a lunisolar calendar, Rosh Hodesh is observed on the day of the new moon. Previously, witnesses who observed the new moon were used to authenticate Rosh Hodesh’s date. This practice is known as kiddush haHodesh (sanctification of the month). News of Rosh Hodesh’s declaration would then spread throughout Israel and the diaspora, depending on whether the Sanhedrin determined it to be a complete (30-day) or defective (29-day) month.

This method was reliant on the Sanhedrin’s ability to establish the month and inform distant Jewish communities of it. This was rendered impracticable in the fourth century CE, and Hillel II instead established a fixed calendar with 29- and 30-day months (see the Hebrew calendar for further information). Rosh Hodesh is observed on the first day of the new month after a 29-day celebration of the previous month. When a month has 30 days left, Rosh Hodesh is observed on the 30th day as well as the first day of the new month.

Observances

Traditional Observances
On Rosh Hodesh, the Amidah’s Avodah benediction is supplemented with the prayer Ya’a’le Ve-Yavo. “Half Hallel” (Psalms 113–118 with the first two paragraphs skipped) is recited during the morning service (except on Rosh Hodesh Tevet, which is during Hanukkah, when Full Hallel is recited). The Torah is read, in particular Numbers 28:1–15, which describes Rosh Hodesh offerings. To honor the Rosh Hodesh sacrifices in the Temple, a second prayer service known as Musaf is added. “Roshe Hadashim” begins the middle blessing. Many recite Psalm 104 after the service.

If Rosh Hodesh falls on Shabbat, Numbers 28:9–15 is read in addition to the regular Torah portion. The German custom to sing the Half Kaddish before Maftir to a particular tune. A unique Rosh Hodesh Haftara is substituted for the normal Haftara. Moreover, when Rosh Hodesh falls on Shabbat, the Musaf prayer is altered. An alternative blessing (Ata Yatzarta) is used in place of the main one, which mentions Rosh Hodesh and Shabbat. If Rosh Hodesh falls on a Sunday, a separate Haftara is read: Mahar Hodesh (I Samuel 20:18–42, “Tomorrow is the New Moon”). Immediately following Rosh Hodesh, usually on the first Saturday night, Kiddush Levana is said.

The Shulchan Aruch advises eating a special meal on Rosh Hodesh, and this practice is common. One now has the chance to say the Ya’a’le Ve-Yavo in Birkat Hamazon.

Moroccan Minhag
The Moroccan minhag’s recitation of Hallel is unique in that it allows for the recitation of two different blessings. Most Sephardic customs require a blessing only on full Hallel; the blessing in this case is “Ligmor et haHallel” (Heb., lit. “To complete the Hallel”). No blessing is said when the shortened Hallel is recited, such as on Rosh Hodesh. The prevailing custom among Ashkenazim is to use the blessing “Likro et haHallel” (Heb., lit. “To read the Hallel”) whether the full or abridged Hallel is read. When the full Hallel is recited, the “Ligmor et haHallel” blessing is said, and the “Likro et haHallel” blessing is read with the abridged Hallel.

Work

Rosh Hodesh is typically treated the same way by Jews today as any other weekday (except for expansion of the prayer service). Work (melacha) is allowed on Rosh Hodesh, according to the Talmud, and the Torah does not forbid it. Women are prohibited from working on Rosh Hodesh, according to the Jerusalem Talmud, but this is simply custom and not a legal requirement. Although the Shulchan Aruch mentions this technique, it doesn’t seem to be used frequently today.

Nonetheless, Rosh Hodesh was observed more seriously in the early Jewish history. Rosh Hodesh is described in certain Biblical sources as a day when no work is done and which appears to have been devoted to worship and feasting. A military commander is instructed to provide commodities on the first of the month, but only to record this delivery in writing on the second of the month, according to an inscription from the Arad ostraca (about 600 BCE), which supports this (seemingly because writing was considered a forbidden melakha).

Several sources claim that Rosh Hodesh was regarded as a day of rest even during the Second Temple period. Work ended (bittul) on Rosh Hodesh, according to a passage from the Talmudic era. Yet, another passage says that labor did not stop (bittul) on this day (assur). Because the musaf sacrifice was made on behalf of the entire populace, Shaagat Aryeh suggested that there was really a general prohibition on Rosh Hodesh work while the Temple was still standing. As a result, it is generally accepted that no one should work on the day that their sacrifice is presented.

Weekday Torah Reading for Rosh Hodesh