Full Moon Dates Calculator for Any Year
Find every full moon date in any year, including named moons like the Harvest Moon and Blue Moon.
Reviewed by Abdullah, Technical Content Specialist
Formula
Full Moon Date = Reference Date + N x 29.530588853 days (synodic period)
Full moon dates are computed by adding multiples of the synodic month (29.530588853 days) to a known reference full moon. The synodic month is the average time between successive full moons, determined by the relative positions of the Sun, Earth, and Moon. More precise calculations include correction terms for orbital eccentricity and perturbations.
Worked Examples
Example 1: Full Moons in 2024
Problem:Find all full moon dates and their traditional names for 2024.
Solution:Using the synodic period of 29.53 days from a known reference:\nJan 25: Wolf Moon\nFeb 24: Snow Moon\nMar 25: Worm Moon\nApr 23: Pink Moon\nMay 23: Flower Moon\nJun 21: Strawberry Moon\nJul 21: Buck Moon\nAug 19: Sturgeon Moon\nSep 17: Harvest Moon (closest to Sep 22 equinox)\nOct 17: Hunter Moon\nNov 15: Beaver Moon\nDec 15: Cold Moon
Result:2024 has 12 full moons, with the Harvest Moon falling on September 17
Example 2: Identifying a Blue Moon Year
Problem:Does 2024 or 2023 contain a Blue Moon (two full moons in one calendar month)?
Solution:2023 full moons: Jan 6, Feb 5, Mar 7, Apr 6, May 5, Jun 3, Jul 3, Aug 1, Aug 30, Sep 29, Oct 28, Nov 27, Dec 26\nAugust 2023 has TWO full moons (Aug 1 and Aug 30)\nThe second one (Aug 30) is a Blue Moon\n2024: No month has two full moons
Result:2023 has a Blue Moon on August 30 (second full moon in August)
Frequently Asked Questions
How are full moon dates calculated?
Full moon dates are calculated using the synodic period of the Moon, which is the time between successive full moons, averaging 29.530588853 days (approximately 29 days, 12 hours, 44 minutes, and 3 seconds). Starting from a known reference full moon, astronomers calculate future and past full moons by adding or subtracting multiples of this period. More precise calculations account for perturbations caused by the Sun gravitational influence, the eccentricity of the Moon orbit, and the tilt of the orbital plane. The Moon orbit is not perfectly circular or stable, so the actual interval between consecutive full moons can vary from about 29.27 to 29.83 days. Professional astronomers use complex mathematical models with many correction terms to predict full moon times to within minutes of accuracy.
What are the traditional names for each monthly full moon?
The traditional full moon names come primarily from Native American, Colonial American, and European traditions. January Wolf Moon is named for wolves howling in the cold winter nights. February Snow Moon reflects the heavy snowfall typical of midwinter. March Worm Moon marks the appearance of earthworm casts as the ground thaws. April Pink Moon celebrates the early spring wildflower phlox subulata. May Flower Moon heralds the abundance of spring flowers. June Strawberry Moon signals the strawberry harvest season. July Buck Moon notes when male deer begin growing new antlers. August Sturgeon Moon comes from the Great Lakes sturgeon fishing season. September or October Harvest Moon is the full moon closest to the autumn equinox. October or November Hunter Moon follows the Harvest Moon. November Beaver Moon marks the beaver trapping season. December Cold Moon acknowledges the long, cold winter nights.
What is a Blue Moon and how often does one occur?
A Blue Moon has two common definitions that are both widely used today. The modern popular definition, which originated from a 1946 Sky and Telescope magazine error, calls the second full moon in a single calendar month a Blue Moon. This occurs roughly once every 2.5 to 3 years because the synodic month (29.53 days) is slightly shorter than most calendar months. The older seasonal definition, used by the Maine Farmers Almanac, defines a Blue Moon as the third full moon in a season that contains four full moons instead of the usual three. By either definition, Blue Moons are not actually blue in color. The phrase once in a blue moon, meaning rarely, predates both astronomical definitions. Actual blue-colored moons can occur due to atmospheric particles from volcanic eruptions or large wildfires scattering red light and letting blue light pass through.
What is a Harvest Moon and why is it special?
The Harvest Moon is the full moon closest to the autumn equinox (around September 22-23 in the Northern Hemisphere), falling in either September or October depending on the year. It is special because of a unique astronomical property: around the autumn equinox, the angle of the Moon orbit relative to the eastern horizon is at its smallest, causing the Moon to rise only about 20-25 minutes later each night instead of the usual 50 minutes. This creates several consecutive evenings with a bright, nearly full moon rising shortly after sunset, providing extra light for farmers to harvest their crops after dark before the invention of electric lighting. The Harvest Moon often appears larger and more orange than usual because it is viewed near the horizon, where atmospheric refraction and scattering enhance its apparent size and color.
References
Reviewed by Abdullah, Technical Content Specialist · Editorial policy