History of New moon in Timeline

By Popular Timelines Editorial Team · Updated: March 14, 2025

In astronomy, the new moon marks the initial lunar phase, occurring when the Moon and the Sun share the same ecliptic longitude. During this phase, the Moon's disk becomes invisible to the unaided eye from Earth, except in the instance of a solar eclipse, where it appears as a silhouette against the Sun.

January 1923: Introduction of Brown's Lunar Theory

In January 1923, specifically on January 17th, the Brown Lunation Number (BLN) was defined, marking the beginning of "lunation 1" with the first new moon. This coincided with the introduction of Ernest William Brown's lunar theory in the American Ephemeris and Nautical Almanac.

January 2000: Introduction of the Lunation Number (LN)

In January 2000, specifically on January 6th, Jean Meeus introduced the Lunation Number (LN), defining lunation 0 as beginning on the first new moon of the year. The LN provides a more recent system for numbering lunations.

2007: Attempt to unify Muslims on a scientifically calculated worldwide calendar

In 2007, the Fiqh Council of North America and the European Council for Fatwa and Research adopted a new calculation for a unified Muslim calendar, requiring conjunction before sunset in Mecca and moonset after sunset on the same evening. This attempt aimed to establish a scientifically calculated worldwide calendar.

2015: Implementation of Twin Holy Birthdays Observance

Effective from 2015, the Baháʼí Faith began observing the "Twin Holy Birthdays" (the birth of the Báb and the birth of Bahá'u'lláh) on the first and second day following the occurrence of the eighth new moon after Naw-Rúz (Baháʼí New Year).