Accurate New Moon Times of 2026 - New Moon & Lunar Phases - Vietnam (UTC+7)

New Moon, Solar Terms, and How to Determine the Lunar New Year

Are you curious about how the lunar calendar determines the first month based on new moon times and solar terms? Let's explore the rules, the role of the new moon, and how to identify leap months in the lunar calendar!

Principles for determining the first lunar month

In the lunar calendar, the first month (Month 1) is the month containing Li Chun (Start of Spring, usually Feb 3-5). It is the first month after the month containing Da Han (Major Cold, around Jan 20-21), starting from the New Moon time.

Role of New Moon and Solar Terms in Leap Years: Adjustments based on Solar Terms

A lunar year usually has 12 months (about 354 days), shorter than a solar year (365.25 days). To balance, the lunar calendar adds a leap month following these rules:

• If there are 13 new moons between two consecutive Winter Solstices, that year will have 13 months, including one leap month.
• A leap month is a month that does not contain any of the 12 major solar terms (Zhongqi) of the year.

Practical Example: New Moon and the 2022 Lunar Calendar

• New Moon on Jan 3, 2022 (01:33): Before Major Cold (Jan 20, 2022), belongs to the 12th lunar month of 2021.
• New Moon on Feb 1, 2022 (12:46): After Major Cold and before Li Chun (Feb 4, 2022), is the 1st lunar month of 2022.