Moon Names

Purpose

Star Almanack names Full Moons according to their relationship to the natural astronomical year rather than according to Gregorian calendar months.

The system is derived in part from the seasonal naming convention preserved by the Maine Farmers’ Almanac, but Star Almanack does not reproduce that system unchanged.

The Maine convention was seasonal rather than simply monthly. Its familiar sequence included:

When a season contained 4 Full Moons, the 3rd was designated the Blue Moon. This allowed the final named Moon of the season to retain its proper seasonal position.

Star Almanack preserves that useful intercalation principle while replacing ecclesiastical and conventional calendar rules with calculated astronomical ones.

Astronomical Seasons

Star Almanack uses the actual calculated equinoxes and solstices as seasonal boundaries.

The Moon names therefore do not depend upon Gregorian months.

They also do not depend upon ecclesiastical calculations of Lent or Easter.

The astronomical calculation comes first. The name is assigned afterward according to the Moon’s relationship to the seasonal structure.

Star Almanack Moon Names

The ordinary sequence is:

Winter

  1. Moon After Yule

  2. Wolf Moon

  3. Sap Moon

Spring

  1. Seed Moon

  2. Milk Moon

  3. Flower Moon

Summer

  1. Hay Moon

  2. Grain Moon

  3. Fruit Moon

Autumn

  1. Harvest Moon

  2. Hunter’s Moon

  3. Moon Before Yule

Star Almanack substitutes Sap Moon for the ecclesiastically associated Lenten Moon and Seed Moon for the Egg/Paschal Moon.

Both replacement names are traditional Moon names rather than names invented by Star Almanack.

Protected Names

Some Moon names describe a specific astronomical relationship and therefore take precedence over an ordinary sequential assignment.

Harvest Moon

The Harvest Moon is the Full Moon nearest the September equinox.

It remains the Harvest Moon whether it occurs before or after the equinox.

Moon Before Yule

The Moon Before Yule is the final Full Moon before the December solstice.

Its name is protected because it describes an astronomical relationship to Yule.

Moon After Yule

The Moon After Yule is the first Full Moon after the December solstice.

Its name is likewise protected.

Blue Moon

Star Almanack uses the traditional seasonal definition of Blue Moon.

When an astronomical season contains 4 Full Moons, the 3rd is designated the:

Blue Moon

The ordinary final Moon name of that season remains attached to the 4th Full Moon.

The Blue Moon therefore functions as an intercalary designation. It absorbs an additional lunation without forcing the ordinary seasonal names out of their intended positions.

Star Almanack does not use the later convention in which the second Full Moon occurring within a Gregorian calendar month is called a Blue Moon.

Frost Moon

Star Almanack normally uses 12 recurring Full Moon names aligned with the natural seasons.

Frost Moon is a 13th name used when the astronomical arrangement places an additional Full Moon between the Hunter’s Moon and the Moon Before Yule.

In such a year, the autumn sequence becomes:

Harvest Moon → Hunter’s Moon → Frost Moon → Moon Before Yule

Frost Moon serves as a shepherd in the Star Almanack naming system. Its purpose is to keep the Harvest Moon and Moon Before Yule in their proper astronomical positions when an additional lunation falls between them. Frost Moon does not displace an ordinary Moon name; it names the otherwise additional lunation so that the anchored names remain where they belong.

Frost Moon is not another form of Blue Moon and should not be confused with it.

A Blue Moon is strictly defined as the 3rd Full Moon in an astronomical season containing 4 Full Moons. When a Full Moon qualifies both for the Frost Moon position and as a Blue Moon, Blue Moon takes precedence.

Frost Moon is therefore a secondary intercalary name. It is used only when the additional late-autumn lunation requires a name and no higher-priority designation applies.

The name Frost Moon is traditional rather than newly coined by Star Almanack. Star Almanack assigns that existing name this specialized shepherding role because its seasonal meaning is appropriate.

In this way, Frost Moon does not alter the astronomical structure of the naming system. It preserves it.

Calculation Principle

Moon names are assigned only after the relevant astronomical events have been calculated.

For each year Star Almanack calculates:

  1. the March equinox

  2. the June solstice

  3. the September equinox

  4. the December solstice

  5. every Full Moon

The calculated events determine the seasonal structure.

Protected names are then assigned.

The seasonal Blue Moon rule is applied where necessary.

The remaining Full Moons receive their ordinary seasonal names.

This makes the naming system a consequence of the astronomy rather than a property of the Gregorian calendar.

2026–2045 Yule-to-Yule Calculation Test

Each cycle begins immediately after the December solstice with the Moon After Yule and ends with the following Moon Before Yule.

Yule is defined astronomically as the December solstice, not as a fixed civil calendar date.

Yule 2025–Yule 2026

Yule 2026–Yule 2027

Yule 2027–Yule 2028

Yule 2028–Yule 2029

Yule 2029–Yule 2030

Yule 2030–Yule 2031

Yule 2031–Yule 2032

Yule 2032–Yule 2033

Yule 2033–Yule 2034

Yule 2034–Yule 2035

Yule 2035–Yule 2036

Yule 2036–Yule 2037

Yule 2037–Yule 2038

Yule 2038–Yule 2039

Yule 2039–Yule 2040

Yule 2040–Yule 2041

Yule 2041–Yule 2042

Yule 2042–Yule 2043

Yule 2043–Yule 2044

Yule 2044–Yule 2045