- 7 Sep, 03:51 Vilnius time: new moon.
- 13 Sep, 23:39 Vilnius time: first quarter.
- 21 Sep, 02:54 Vilnius time: full moon, traditionally the Harvest Moon.
- 29 Sep, 04:57 Vilnius time: last quarter.
- During September 2021 the Moon passes through all eight phases. One full cycle takes about 29.5 days.
- The next full moon after this month is on 20 October 2021 (October 2021).
Moon phase times, September 2021
The four principal phases are moments, not whole days. Times are given in UTC and in Europe/Vilnius time.
| Date | Phase | Europe/Vilnius | UTC |
|---|---|---|---|
| Tue 7 Sep | New moon | 03:51 | 00:51 |
| Mon 13 Sep | First quarter | 23:39 | 20:39 |
| Tue 21 Sep | Full moon · Harvest Moon | 02:54 | 23:54 |
| Wed 29 Sep | Last quarter | 04:57 | 01:57 |
The sky: September 2021
Planets and sky events this month, as seen in London. The Moon's phases are in the calendar above.
Planets visible (mid-month)
Events
| Thu 9 Sep | The Moon near Mercury | About 5.9° apart, but Mercury is not visible that night. |
| Fri 10 Sep | The Moon near Venus | About 3.7° apart, but Venus is not visible that night. |
| Tue 14 Sep | Mercury farthest from the Sun | 27° in the evening sky. Too low at this latitude this time, hard to see. |
| Fri 17 Sep | The Moon near Saturn | About 3.7° apart. Look for Saturn next to the Moon. |
| Sat 18 Sep | The Moon near Jupiter | About 3.8° apart. Look for Jupiter next to the Moon. |
How to read the moon calendar
Each day shows its date, the share of the Moon’s disc that is lit at noon, and the Moon’s shape that day. When a full moon, new moon or quarter falls on a day, it is named at the bottom of the cell.
Illumination is the part of the disc lit by the Sun. It grows from new moon to full moon (waxing) and shrinks from full moon to new moon (waning). Each day opens its own page with every signal for that date.
Full moon dates 2021
| Date | Time (UTC) | Traditional name | |
|---|---|---|---|
| Thu 28 Jan | 19:16 | Wolf Moon | passed |
| Sat 27 Feb | 08:17 | Snow Moon | passed |
| Sun 28 Mar | 18:48 | Worm Moon | passed |
| Tue 27 Apr | 03:31 | Pink Moon | passed |
| Wed 26 May | 11:13 | Flower Moon | passed |
| Thu 24 Jun | 18:39 | Strawberry Moon | passed |
| Sat 24 Jul | 02:36 | Buck Moon | passed |
| Sun 22 Aug | 12:01 | Sturgeon Moon | passed |
| Tue 21 Sep | 23:54 | Harvest Moon | passed |
| Wed 20 Oct | 14:56 | Hunter’s Moon | passed |
| Fri 19 Nov | 08:57 | Beaver Moon | passed |
| Sun 19 Dec | 04:35 | Cold Moon | passed |
New moon dates 2021
| Date | Time (UTC) | |
|---|---|---|
| Wed 13 Jan | 05:00 | passed |
| Thu 11 Feb | 19:05 | passed |
| Sat 13 Mar | 10:21 | passed |
| Mon 12 Apr | 02:30 | passed |
| Tue 11 May | 18:59 | passed |
| Thu 10 Jun | 10:52 | passed |
| Sat 10 Jul | 01:16 | passed |
| Sun 8 Aug | 13:50 | passed |
| Tue 7 Sep | 00:51 | passed |
| Wed 6 Oct | 11:05 | passed |
| Thu 4 Nov | 21:14 | passed |
| Sat 4 Dec | 07:43 | passed |
The eight moon phases explained
Four principal phases are exact instants; the four in between are the days that connect them.
Solar and lunar eclipses in 2021
No eclipse data for 2021.
The waning moon is traditionally a time for finishing
Questions people ask
When is the full moon in September 2021?
The full moon is on 21 September 2021. Its traditional name is the Harvest Moon. The exact time is in the table on this page.
When is the new moon in September 2021?
The new moon is on 7 September 2021. The Moon can’t be seen that night: it sits between Earth and the Sun with its lit side turned away.
What do the percentages mean?
They show how much of the Moon’s disc is lit at noon. 0% is new moon, 100% is full moon and 50% is a quarter.
Why does another calendar give a different date?
A phase is a moment. When it falls near midnight, the date can differ by one day between time zones. This calendar uses Europe/Vilnius time for the days.
How often is there a full moon?
About every 29.5 days. Some months have two; the second is called a Blue Moon.
- Jean Meeus, Astronomical Algorithms, 2nd ed., Willmann-Bell, 1998, chapters 48 and 49.
- NASA Eclipse Web Site (eclipse dates and visibility).
Numbers update through the day from public sources. The text for each day is written from that day’s data and checked by the editor. Every past day keeps its own page in the archive.