Uposatha, full-moon and new-moon days
Across Buddhist traditions the moon sets a rhythm for practice. Days of the new moon and the full moon, and in some places the half moons, are set apart for extra effort. This page explains what that means and how it looks in Vietnam. For the dates of the year, see the calendar.
What uposatha means
Uposatha is a Pali word for an observance day. Its roots are in the earliest monastic communities, where monks and nuns gathered on the new-moon and full-moon days to recite their rules and to say aloud any fault they had made. In Vietnamese the gathering is called bố tát. The idea is regular, shared renewal.
For monastics and for lay people
- Monastics. The fortnightly gathering is the core. In many countries the full-moon and new-moon days are public holidays or quiet days in the temple.
- Lay people. Some followers spend the day at a temple, listen to teaching, practise meditation, and keep eight precepts for a day. These are the five precepts, with the third becoming complete abstention from sexual activity, plus: no food after midday, no entertainment, perfume or adornment, and no high or luxurious seats and beds. Vietnamese temples call a one-day retreat of this kind bát quan trai (eight-precept day); not every temple offers it.
Taking these precepts is a personal choice. Nobody is required to do so, and the page makes no claim about what a person gains from it.
In Theravada countries
In Thailand, Sri Lanka, Cambodia, Myanmar and Laos, the observance days follow the local lunar calendar, usually the full moon, the new moon and the two half-moon days, so about four a month. Local custom sets which days are public.
In Vietnam
Most Vietnamese temples, in the Mahayana tradition, give the first day of the month (mùng một) and the full-moon day (rằm) the greatest weight. Many people eat vegetarian food on these days, go to the temple, offer flowers, and join chanting. Some temples hold a repentance service. The Khmer and other southern communities that follow the Theravada tradition keep their own days. Ways of keeping the days differ from place to place.
A date can differ by a day between countries because each calendar uses a different time zone and sometimes a different counting rule. Look at the calendar of the temple you plan to visit.
See also
- Buddhist calendar for computed dates.
- Festivals for the larger yearly occasions.
- Glossary for the terms above.
Related pages
- Buddhist calendarFull and new moon days, Buddha's Birthday, Vu Lan, Avalokiteshvara days, Amitabha day and Bodhi Day for this year and the next, converted to the Gregorian calendar from the Vietnamese lunar calendar.
- Festivals in Vietnamese Buddhist templesWhat Tet, Buddha's Birthday, Vu Lan and the first and full-moon days mean at the temple and what people usually do. Dates are on the calendar page.
- Buddhist basics in plain wordsThe Three Jewels, the Four Noble Truths, the Eightfold Path, the Five Precepts, and karma and rebirth, explained briefly and neutrally for people who are new to Buddhism.
- How to pay respects at a Vietnamese templeA step-by-step visit: what to wear, how to behave, incense, offerings, palms together and bowing, bell and wooden fish, sitting meditation, and what to avoid.
Keep reading
- Buddhist basics in plain words
- Layout of a Vietnamese Buddhist temple
- The altars of a Vietnamese temple
- How to pay respects at a Vietnamese temple
- Buddhist calendar
- Buddhist glossary for temple visitors
- Avalokiteshvara (Quan Thế Âm), the one who listens
- The Buddha's awakening
- Two Jataka tales
- Maudgalyayana and filial gratitude
- Visiting a Vietnamese temple: common questions
- Temple etiquette: how to behave in a Vietnamese temple
- Offerings: what flowers, fruit, water, lamps and incense mean
- Festivals in Vietnamese Buddhist temples
- Kisa Gotami and the mustard seed
- The blind men and the elephant
- The poisoned arrow
- Angulimala, the road back
- Ksitigarbha (Địa Tạng) and the vow
- Sujata and the bowl of milk rice