Introduction

The following table gives the date and time (Universal Time) of the Moon's phases for 100 years. This data is of particular use to historical research projects.

The length of the mean synodic month (New Moon to New Moon) as calculated for the year 2000 is 29.530588 days (= 29d 12h 44m 03s). However, the length of any one synodic month can vary from 29.26 to 29.80 days due to perturbing effects of the Sun on the Moon's eccentric orbit. For example, see Length of the Synodic Month: 2001 to 2100.

For conversion to time zones other than Universal Time, see Time Zones. If Daylight Saving Time is in effect, add one hour to the times listed.

Historians should note that the astronomical dating system used in these tables includes the year "0" while the traditional BCE - CE dating convention does not. Thus, the year "0" here corresponds to "1 BCE", the year "-100" is "101 BCE", and so on. The old style Julian calendar is used for dates prior to 1582 Oct 15, while the modern Gregorian calendar is used after that date. For more information, see calendar dates.

If an eclipse of the Sun or Moon takes place on a given date, it is indicated to the right of the date by a single character representing the type of eclipse. Abbreviations for the different types of eclipses appear below.

An eclipse of the Sun can occur only at New Moon (see: Solar Eclipses for Beginners), while an eclipse of the Moon can occur only at Full Moon (see: Lunar Eclipses for Beginners). In any calendar year there are a minimum of two solar and two lunar eclipses. The maximum number of eclipses in one year is 7 (4 solar and 3 lunar, or 5 solar and 2 lunar). Information about upcoming eclipses can be found at Solar Eclipse Preview and Lunar Eclipse Preview.

The values of ΔT used to convert Dynamical Time to Universal Time in this 100-year table range from 17.9 to 12.1 minutes. The uncertainty in the value of ΔT grows large for dates in the distant past or future.