Waning Crescent Moon Definition

What is a waning crescent moon? The waning crescent moon, sometimes called an old moon, is defined to occur when the Moon is nearly, but not precisely, on a line with the Earth and Sun. This means that part but less than one-half of the Moon is illuminated by direct sunlight, creating a crescent moon. Because the fraction of the Moon’s disk that is illuminated is decreasing, we consider the Moon to be “waning.” Each new lunar cycle is measured beginning at each new moon and the waning crescent moon occurs when the Moon is more than three-quarters of the way around the sky (i.e., along its orbit) from new moon.

Waning Crescent Moon Dates / Next Waning Crescent Moon

When is the next waning crescent moon? A waning crescent moon is seen one day to several days before a new moon. The average calendrical month, which is 1/12 of a year, is about 30.44 days, while the Moon’s phase (synodic) cycle repeats on average every 29.53 days. Therefore the timing of the Moon’s phases shifts by an average of almost one day for each successive month. To find out the waning crescent moon dates, please see the waning crescent moon calendar below.

Waning Crescent Moon and The Moon Phases

Waning Crescent Moon

Waning Crescent Moon

The waning crescent moon, happens when the moon is between a 135 and 180 degree angle with respect to the Earth and Sun. So we are seeing less than half of the moon illuminated and more than half in shadow. The word “crescent” refers to the phases where the moon is less that half illuminated. “Waning” essentially means shrinking or decreasing in illumination. Each evening, as the moon’s orbital motion carries it away from the Earth-sun line, we see less of the moon’s day side.

Each lunar cycle begins with a new moon. As the Moon moves eastward away from the Sun in the sky, we see a bit more of the sunlit side of the Moon each night. We call this waxing. After the new moon, the sunlit portion is increasing, but less than half illuminated, so it is a waxing crescent moon. When half of the Moon’s disc is illuminated, we call it the first quarter moon. As the sunlit portion continues to increase, now more than half illuminated, it becomes waxing gibbous moon. When the Moon reaches maximum illumination, a full moon, the Moon has completed one half of the lunar month.

During the second half of the lunar month, the Moon grows thinner each night. We call this waning. The waning gibbous moon phase occurs first, followed by the last quarter moon when half of the Moon’s disc is illuminated. Next is the waning crescent moon, which wanes until the illumination is completely gone; a new moon.

Waning Crescent Moon Calendar 2012

The waning crescent moon calendar for 2012 is expressed in Coordinated Universal Time (UT), the international basis for other time zones, and occurs on the days between each last quarter moon and new moon. On these days, the waning crescent is up in the sky, nearly all day long, moving ahead of the sun across the sky’s dome. It sets in the west several hours or less before sunset. Astronomers call one lunar cycle a lunation. For waning crescent moon times in your city, please use the Time Zone Converter.

Lunation New Moon First Quarter Full Moon Last Quarter
1001   Jan 1 06:15 Jan 9 07:30 Jan 16 09:08
1002 Jan 23 7:39 Jan 31 04:10 Feb 7 21:54 Feb 14 17:04
1003 Feb 21 22:35 Mar 1 01:22 Mar 8 09:40 Mar 15 01:25
1004 Mar 22 14:37 Mar 30 19:41 Apr 6 19:19 Apr 13 10:50
1005 Apr 21 07:18 Apr 29 09:58 May 6 03:35 May 12 21:47
1006 May 20 23:47 May 28 20:16 Jun 4 11:12 Jun 11 10:41
1007 Jun 19 15:02 Jun 27 03:30 Jul 3 18:52 Jul 11 01:48
1008 Jul 19 04:24 Jul 26 08:56 Aug 2 03:27 Aug 9 18:55
1009 Aug 17 15:54 Aug 24 13:54 Aug 31 13:58 Sep 8 13:15
1010 Sep 16 02:11 Sep 22 19:41 Sep 30 03:19 Oct 8 07:33
1011 Oct 15 12:02 Oct 22 03:32 Oct 29 19:50 Nov 7 00:36
1012 Nov 13 22:08 Nov 20 14:31 Nov 28 14:46 Dec 6 15:32
1013 Dec 13 08:42 Dec 20 05:19 Dec 28 10:21  

Crescent Moon

A crescent moon has nothing to do with Earth’s shadow on the moon. The only time Earth’s shadow can fall on the moon is at full moon, during a lunar eclipse. There is a shadow on a crescent moon, but it’s the moon’s own shadow. Night on the moon happens on the part of the moon submerged in the moon’s own shadow. Likewise, night on Earth happens on the part of Earth submerged in Earth’s own shadow.

Moon Phases, Full Moons and Moon Calendars

As the Moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

Full Moons

Full Moon | Full Moon Names | Blue Moon | Wolf Moon | Snow Moon | Worm Moon | Pink Moon | Flower Moon | Strawberry Moon | Buck Moon | Sturgeon Moon | Harvest Moon | Hunters Moon | Beaver Moon | Cold Moon |

Moon Phases

Understanding Moon Phases | New Moon | Waxing Crescent Moon | First Quarter Moon | Waxing Gibbous Moon | Full Moon | Waning Gibbous Moon | Last Quarter Moon | Waning Crescent Moon |

Moon Calendars

Full Moon Calendar | Lunar Calendar | Lunar Eclipse Calendar | Solar Eclipse Calendar | Full Moon Calendar 2011 | Full Moon Calendar 2012 | Full Moon Calendar 2013 | Full Moon Calendar 2014 | Full Moon Calendar 2015 | Full Moon Calendar 2016 | Full Moon Calendar 2017 | Full Moon Calendar 2018 | Full Moon Calendar 2019 | Full Moon Calendar 2020 |

Eclipses & Moon Facts

Lunar Eclipse | Solar Eclipse | Solar Eclipse vs. Lunar Eclipse | Facts About The Moon |