Observances held on the new moon

traditional Thai New Year's holiday based on the sidereal year

Tết (, ), short for '''''' (; ), is the most important celebration in Vietnamese culture. Tết celebrates the arrival of spring, which is on the first day of the first Vietnamese lunisolar month, and usually falls between late January and 20 February in the Gregorian calendar.

Losar (; "new year"), also known as the Tibetan New Year, is a festival in Tibetan Buddhism. The holiday is celebrated on various dates depending on location tradition (Tibet, Bhutan, Nepal, Arunachal Pradesh, Sikkim and Ladakh). The holiday is a new year's festival, celebrated on the first day of the lunisolar Tibetan calendar, which corresponds to a date in February or March in the Gregorian calendar. In 2025, the new year commenced on February 28 and was celebrated until March 2. It also commenced the Year of the Female Wood Snake.

day off to commemorate January 1 in the lunar calendar in Korea

first day of each Hebrew month

An Uposatha (; ) day is a Buddhist day of observance, in existence since the Buddha's time (600 BCE), and still being kept today by Buddhist practitioners. The Buddha taught that the Uposatha day is for "the cleansing of the defiled mind," resulting in inner calm and joy. On this day, both lay and ordained members of the sangha intensify their practice, deepen their knowledge and express communal commitment through millennia-old acts of lay-monastic reciprocity. On these days, the lay followers make a conscious effort to keep the Five Precepts or (as the tradition suggests) the ten precepts. I

Amavasya () represents the lunar phase of new moon in the Hindu calendar. A calendar month ends on amavasya as per the amanta tradition of the Hindu lunar calendar. Various Hindu beliefs and rituals are associated with the day. Hindu festivals including Diwali are celebrated on the amavasya day of various months.

The Noumenia (, lit: new moon) is the first day of the lunar month and also a religious observance in ancient Athens and much of Greece (cf. Attic calendar).

Festival in Thailand