Moon phase calendar 2030

2030 carries twelve full moons and 13 new moons — the ordinary arrangement, where each calendar month gets exactly one full moon and the dates walk steadily backwards through the year.

The moon phase calendar 2030 below lists all of them, in your own timezone, with the exact instant rather than the date alone. Every time on this page is searched for individually in the ephemeris rather than stepped forward from the one before, because the lunation length varies enough that adding 29.53 days repeatedly drifts off within months.

One thing the table will not do is round to the day. Instants matter here more than they look like they should: the difference between a full moon at 23:40 and one at 00:20 is a whole calendar date, and which side of midnight it falls on depends on where the reader is standing rather than on anything about the Moon.

The shortest lunar cycle of 2030 runs 29.43 days and the longest 29.67 — a spread of about 6 hours between them. That variation comes from the Moon's elliptical orbit: it moves fastest at perigee, so the cycles that contain a perigee near new moon finish sooner.

A lunation is not a fixed length. In 2030 the shortest runs 29.43 days, from the new moon on September 27, and the longest runs 29.67 days, from the one on April 2 — a difference of about 6 hours between two consecutive months of the same cycle.

The cause is the shape of the orbit. The Moon travels along an ellipse, moving fastest near perigee and slowest near apogee, so a cycle that happens to contain its perigee close to the new moon gets through the 360° of elongation sooner. Over a year the effect is large enough to matter: adding 29.53 days repeatedly to a known new moon drifts off the real dates within a few months, which is why every instant on this page is searched for individually rather than stepped forward from the one before.

This is also the answer to a question the table above raises for anyone who studies it. The gaps between consecutive full moons are not equal, the gaps between a full moon and the next first quarter are not equal, and neither pattern repeats from year to year. The moon phase calendar 2030 above spaces them where they actually fall; one that spaces its events evenly is drawing the idea of a lunation rather than the real one.