Variation in number of days between full moons

So how long is it between one full moon and the next?

The typical answer is 29 and a half days. However it can range between 29.8 days and 29.3 days.

More intrestingly the variation between the max and min number of days varies from year to year. In some years the variation can be more than half a day, in other years the diferance might be only a quater of a day.

For the real maths heads amongst you a spectral analysis gives two dominant frequencies of 1/413 days and 1/362 days. I.E. with dominant frequency of once every 413 days and beat frequency once every 7.92 years.

 

abs of Fourier coeff Frequency, cycles per 5787.87 days Wave Length (years:days)
17.2752 14 1 y 48 days
8.3210 16 361 days
2.9044 15  
1.8641 13  
1.1522 28  

The above graph has been based on data from U.S. Naval Observatory Astronomical Applications Department

NEW MOON	    FIRST QUARTER	FULL MOON   	LAST QUARTER	Days between full moons
        	    04/01/90 10:40	11/01/90 04:57	18/01/90 21:17	
26/01/90 19:20	02/02/90 18:32	09/02/90 19:16	17/02/90 18:48	29.60
25/02/90 08:54	04/03/90 02:05	11/03/90 10:58	19/03/90 14:30	29.65
26/03/90 19:48	02/04/90 10:24	10/04/90 03:18	18/04/90 07:02	29.68
25/04/90 04:27	01/05/90 20:18	09/05/90 19:31	17/05/90 19:45	29.68
24/05/90 11:47	31/05/90 08:11	08/06/90 11:01	16/06/90 04:48	29.65
22/06/90 18:55	29/06/90 22:07	08/07/90 01:23	15/07/90 11:04	29.60
22/07/90 02:54	29/07/90 14:01	06/08/90 14:19	13/08/90 15:54	29.54
20/08/90 12:39	28/08/90 07:34	05/09/90 01:46	11/09/90 20:53	29.48
19/09/90 00:46	27/09/90 02:06	04/10/90 12:02	11/10/90 03:31	29.43
18/10/90 15:37	26/10/90 20:26	02/11/90 21:48	09/11/90 13:02	29.41
17/11/90 09:05	25/11/90 13:11	02/12/90 07:50	09/12/90 02:04	29.42
17/12/90 04:22	25/12/90 03:16	31/12/90 18:35	07/01/91 18:35	29.45
15/01/91 23:50	23/01/91 14:21	30/01/91 06:10	06/02/91 13:52	29.48
14/02/91 17:32	21/02/91 22:58	28/02/91 18:25	08/03/91 10:32	29.51
16/03/91 08:10	23/03/91 06:03	30/03/91 07:17	07/04/91 06:45	29.54
14/04/91 19:38	21/04/91 12:39	28/04/91 20:58	07/05/91 00:46	29.57
14/05/91 04:36	20/05/91 19:46	28/05/91 11:37	05/06/03 15:30	29.61
12/06/91 12:06	19/06/91 04:19	27/06/91 02:58	05/07/91 02:50	29.64
11/07/91 19:06	18/07/91 15:11	26/07/91 18:24	03/08/91 11:25	29.64
10/08/91 02:28	17/08/91 05:01	25/08/91 09:07	01/09/91 18:16	29.61
08/09/91 11:01	15/09/91 22:01	23/09/91 22:40	01/10/91 00:30	29.56
07/10/91 21:39	15/10/91 17:33	23/10/91 11:08	30/10/91 07:10	29.52
06/11/91 11:11	14/11/91 14:02	21/11/91 22:56	28/11/91 15:21	29.49
06/12/91 03:56	14/12/91 09:32	21/12/91 10:23	28/12/91 01:55	29.48
04/01/92 23:10	13/01/92 02:32	19/01/92 21:28	26/01/92 15:27	29.46
03/02/92 19:00	11/02/92 16:15	18/02/92 08:04	25/02/92 07:56	29.44
04/03/92 13:22	12/03/92 02:36	18/03/92 18:18	26/03/92 02:30	29.43
03/04/92 05:01	10/04/92 10:06	17/04/92 04:42	24/04/92 21:40	29.43
02/05/92 17:44	09/05/92 15:43	16/05/92 16:03	24/05/92 15:53	29.47
01/06/92 03:57	07/06/92 20:47	15/06/92 04:50	23/06/92 08:11	29.53
30/06/92 12:18	07/07/92 02:43	14/07/92 19:06	22/07/92 22:12	29.59
29/07/92 19:35	05/08/92 10:58	13/08/92 10:27	21/08/92 10:01	29.64
28/08/92 02:42	03/09/92 22:39	12/09/92 02:17	19/09/92 19:53	29.66
26/09/92 10:40	03/10/92 14:12	11/10/92 18:03	19/10/92 04:12	29.66
25/10/92 20:34	02/11/92 09:11	10/11/92 09:20	17/11/92 11:39	29.64
24/11/92 09:11	02/12/92 06:17	09/12/92 23:41	16/12/92 19:13	29.60
24/12/92 00:43	01/01/93 03:38	08/01/93 12:37	15/01/93 04:01	29.54
22/01/93 18:27	30/01/93 23:20	06/02/93 23:55	13/02/93 14:57	29.47
21/02/93 13:05	01/03/93 15:46	08/03/93 09:46	15/03/93 04:16	29.41
23/03/93 07:14	31/03/93 04:10	06/04/93 18:43	13/04/93 19:39	29.37
21/04/93 23:49	29/04/93 12:40	06/05/93 03:34	13/05/93 12:20	29.37
21/05/93 14:06	28/05/93 18:21	04/06/93 13:02	12/06/93 05:36	29.39
20/06/93 01:52	26/06/93 22:43	03/07/93 23:45	11/07/93 22:49	29.45
19/07/93 11:24	26/07/93 03:25	02/08/93 12:10	10/08/93 15:19	29.52
17/08/93 19:28	24/08/93 09:57	01/09/93 02:33	09/09/93 06:26	29.60
16/09/93 03:10	22/09/93 19:32	30/09/93 18:54	08/10/93 19:35	29.68
15/10/93 11:36	22/10/93 08:52	30/10/93 12:38	07/11/93 06:36	29.74
13/11/93 21:34	21/11/93 02:03	29/11/93 06:31	06/12/93 15:49	29.75
13/12/93 09:27	20/12/93 22:26	28/12/93 23:05	05/01/94 00:00	29.69
11/01/94 23:10	19/01/94 20:27	27/01/94 13:23	03/02/94 08:06	29.60
10/02/94 14:30	18/02/94 17:47	26/02/94 01:15	04/03/94 16:53	29.49
12/03/94 07:05	20/03/94 12:14	27/03/94 11:09	03/04/94 02:55	29.41
11/04/94 00:17	19/04/94 02:34	25/04/94 19:45	02/05/94 14:32	29.36
10/05/94 17:07	18/05/94 12:50	25/05/94 03:39	01/06/94 04:02	29.33
09/06/94 08:26	16/06/94 19:56	23/06/94 11:33	30/06/94 19:31	29.33
08/07/94 21:37	16/07/94 01:12	22/07/94 20:16	30/07/94 12:40	29.36
07/08/94 08:45	14/08/94 05:57	21/08/94 06:47	29/08/94 06:41	29.44
05/09/94 18:33	12/09/94 11:34	19/09/94 20:00	28/09/94 00:23	29.55
05/10/94 03:55	11/10/94 19:17	19/10/94 12:18	27/10/94 16:44	29.68
03/11/94 13:35	10/11/94 06:14	18/11/94 06:57	26/11/94 07:04	29.78
02/12/94 23:54	09/12/94 21:06	18/12/94 02:17	25/12/94 19:06	29.81
01/01/95 01:56	08/01/95 15:46	16/01/95 20:26	24/01/95 04:58	29.76
30/01/95 22:48	07/02/95 12:54	15/02/95 12:15	22/02/95 13:04	29.66
01/03/95 11:48	09/03/95 10:14	17/03/95 01:26	23/03/95 20:10	29.55
31/03/95 02:09	08/04/95 05:35	15/04/95 12:08	22/04/95 03:18	29.45
29/04/95 17:36	07/05/95 21:44	14/05/95 20:48	21/05/95 11:36	29.36
29/05/95 09:27	06/06/95 10:26	13/06/95 04:03	19/06/95 22:01	29.30
28/06/95 00:50	05/07/95 20:02	12/07/95 10:49	19/07/95 11:10	29.28
27/07/95 15:13	04/08/95 03:16	10/08/95 18:15	18/08/95 03:04	29.31
26/08/95 04:31	02/09/95 09:03	09/09/95 03:37	16/09/95 21:09	29.39
24/09/95 16:55	01/10/95 14:36	08/10/95 15:52	16/10/95 16:26	29.51
24/10/95 04:36	30/10/95 21:17	07/11/95 07:20	15/11/95 11:40	29.64
22/11/95 15:43	29/11/95 06:28	07/12/95 01:27	15/12/95 05:31	29.75
22/12/95 02:22	28/12/95 19:06	05/01/96 20:51	13/01/96 20:45	29.81
20/01/96 12:50	27/01/96 11:14	04/02/96 15:58	12/02/96 08:37	29.80
18/02/96 23:30	26/02/96 05:52	05/03/96 09:23	12/03/96 17:15	29.73
19/03/96 10:45	27/03/96 01:31	04/04/96 00:07	10/04/96 23:36	29.61
17/04/96 22:49	25/04/96 20:40	03/05/96 11:48	10/05/96 05:04	29.49
17/05/96 11:46	25/05/96 14:13	01/06/96 20:47	08/06/96 11:05	29.37
16/06/96 01:36	24/06/96 05:23	01/07/96 03:58	07/07/96 18:55	29.30
15/07/96 16:15	23/07/96 17:49	30/07/96 10:35	06/08/96 05:25	29.28
14/08/96 07:34	22/08/96 03:36	28/08/96 17:52	04/09/96 19:06	29.30
12/09/96 23:07	20/09/96 11:23	27/09/96 02:51	04/10/96 12:04	29.37
12/10/96 14:14	19/10/96 18:09	26/10/96 14:11	03/11/96 07:50	29.47
11/11/96 04:16	18/11/96 01:09	25/11/96 04:10	03/12/96 05:06	29.58
10/12/96 16:56	17/12/96 09:31	24/12/96 20:41	02/01/97 01:45	29.69
09/01/97 04:26	15/01/97 20:02	23/01/97 15:11	31/01/97 19:40	29.77
07/02/97 15:06	14/02/97 08:57	22/02/97 10:27	02/03/97 09:37	29.80
09/03/97 01:15	16/03/97 00:06	24/03/97 04:45	31/03/97 19:38	29.76
07/04/97 11:02	14/04/97 17:00	22/04/97 20:33	30/04/97 02:37	29.66
06/05/97 20:46	14/05/97 10:55	22/05/97 09:13	29/05/97 07:51	29.53
05/06/97 07:03	13/06/97 04:51	20/06/97 19:09	27/06/97 12:42	29.41
04/07/97 18:40	12/07/97 21:44	20/07/97 03:20	26/07/97 18:28	29.34
03/08/97 08:14	11/08/97 12:42	18/08/97 10:55	25/08/97 02:23	29.32
01/09/97 23:52	10/09/97 01:31	16/09/97 18:50	23/09/97 13:35	29.33
01/10/97 16:51	09/10/97 12:22	16/10/97 03:46	23/10/97 04:48	29.37
31/10/97 10:01	07/11/97 21:43	14/11/97 14:12	21/11/97 23:58	29.43
30/11/97 02:14	07/12/97 06:09	14/12/97 02:37	21/12/97 21:43	29.52
29/12/97 16:56	05/01/98 14:18	12/01/98 17:24	20/01/98 19:40	29.62
28/01/98 06:01	03/02/98 22:53	11/02/98 10:23	19/02/98 15:27	29.71
26/02/98 17:26	05/03/98 08:41	13/03/98 04:34	21/03/98 07:38	29.76
28/03/98 03:14	03/04/98 20:18	11/04/98 22:23	19/04/98 19:53	29.74
26/04/98 11:41	03/05/98 10:04	11/05/98 14:29	19/05/98 04:35	29.67
25/05/98 19:32	02/06/98 01:45	10/06/98 04:18	17/06/98 10:38	29.58
24/06/98 03:50	01/07/98 18:43	09/07/98 16:01	16/07/98 15:13	29.49
23/07/98 13:44	31/07/98 12:05	08/08/98 02:10	14/08/98 19:48	29.42
22/08/98 02:03	30/08/98 05:06	06/09/98 11:21	13/09/98 01:58	29.38
20/09/98 17:01	28/09/98 21:11	05/10/98 20:12	12/10/98 11:11	29.37
20/10/98 10:09	28/10/98 11:46	04/11/98 05:18	11/11/98 00:28	29.38
19/11/98 04:27	27/11/98 00:23	03/12/98 15:19	10/12/98 17:53	29.42
18/12/98 22:42	26/12/98 10:46	02/01/99 02:49	09/01/99 14:22	29.48
17/01/99 15:46	24/01/99 19:15	31/01/99 16:06	08/02/99 11:58	29.55
16/02/99 06:39	23/02/99 02:43	02/03/99 06:58	10/03/99 08:40	29.62
17/03/99 18:48	24/03/99 10:18	31/03/99 22:49	09/04/99 02:51	29.66
16/04/99 04:22	22/04/99 19:01	30/04/99 14:55	08/05/99 17:28	29.67
15/05/99 12:05	22/05/99 05:34	30/05/99 06:40	07/06/99 04:20	29.66
13/06/99 19:03	20/06/99 18:13	28/06/99 21:37	06/07/99 11:57	29.62
13/07/99 02:24	20/07/99 09:00	28/07/99 11:25	04/08/99 17:27	29.58
11/08/99 11:08	19/08/99 01:47	26/08/99 23:48	02/09/99 22:17	29.52
09/09/99 22:02	17/09/99 20:06	25/09/99 10:51	02/10/99 04:02	29.46
09/10/99 11:34	17/10/99 15:00	24/10/99 21:02	31/10/99 12:04	29.42
08/11/99 03:53	16/11/99 09:03	23/11/99 07:04	29/11/99 23:18	29.42
07/12/99 22:32	16/12/99 00:50	22/12/99 17:31	29/12/99 14:04	29.44
06/01/00 01:14	14/01/00 13:34	21/01/00 04:40	28/01/00 07:57	29.46
05/02/00 13:03	12/02/00 23:21	19/02/00 16:27	27/02/00 03:53	29.49
06/03/00 05:17	13/03/00 06:59	20/03/00 04:44	28/03/00 00:21	29.51
04/04/00 18:12	11/04/00 13:30	18/04/00 17:41	26/04/00 19:30	29.54
04/05/00 04:12	10/05/00 20:00	18/05/00 07:34	26/05/00 11:55	29.58
02/06/00 12:14	09/06/00 03:29	16/06/00 22:27	25/06/00 01:00	29.62
01/07/00 19:20	08/07/00 12:53	16/07/00 13:55	24/07/00 11:02	29.64
31/07/00 02:25	07/08/00 01:02	15/08/00 05:13	22/08/00 18:51	29.64
29/08/00 10:19	05/09/00 16:27	13/09/00 19:37	21/09/00 01:28	29.60
27/09/00 19:53	05/10/00 10:59	13/10/00 08:53	20/10/00 07:59	29.55
27/10/00 07:58	04/11/00 07:27	11/11/00 21:15	18/11/00 15:24	29.52
25/11/00 23:11	04/12/00 03:55	11/12/00 09:03	18/12/00 00:41	29.49
25/12/00 17:22	02/01/01 22:31	09/01/01 20:24	16/01/01 12:35	29.47
24/01/01 13:07	01/02/01 14:02	08/02/01 07:12	15/02/01 03:23	29.45
23/02/01 08:21	03/03/01 02:03	09/03/01 17:23	16/03/01 20:45	29.42
25/03/01 01:21	01/04/01 10:49	08/04/01 03:22	15/04/01 15:31	29.42
23/04/01 15:26	30/04/01 17:08	07/05/01 13:52	15/05/01 10:11	29.44
23/05/01 02:46	29/05/01 22:09	06/06/01 01:39	14/06/01 03:28	29.49
21/06/01 11:58	28/06/01 03:19	05/07/01 15:04	13/07/01 18:45	29.56
20/07/01 19:44	27/07/01 10:08	04/08/01 05:56	12/08/01 07:53	29.62
19/08/01 02:55	25/08/01 19:55	02/09/01 21:43	10/09/01 18:59	29.66
17/09/01 10:27	24/09/01 09:31	02/10/01 13:49	10/10/01 04:20	29.67
16/10/01 19:23	24/10/01 02:58	01/11/01 05:41	08/11/01 12:21	29.66
15/11/01 06:40	22/11/01 23:21	30/11/01 20:49	07/12/01 19:52	29.63
14/12/01 20:47	22/12/01 20:56	30/12/01 10:40	06/01/02 03:55	29.58
13/01/02 13:29	21/01/02 17:46	28/01/02 22:50	04/02/02 13:33	29.51
12/02/02 07:41	20/02/02 12:02	27/02/02 09:17	06/03/02 01:24	29.44
14/03/02 02:02	22/03/02 02:28	28/03/02 18:25	04/04/02 15:29	29.38
12/04/02 19:21	20/04/02 12:48	27/04/02 03:00	04/05/02 07:16	29.36
12/05/02 10:45	19/05/02 19:42	26/05/02 11:51	03/06/02 00:05	29.37
10/06/02 23:46	18/06/02 00:29	24/06/02 21:42	02/07/02 17:19	29.41
10/07/02 10:26	17/07/02 04:47	24/07/02 09:07	01/08/02 10:22	29.48
08/08/02 19:15	15/08/02 10:12	22/08/02 22:29	31/08/02 02:31	29.56
07/09/02 03:10	13/09/02 18:08	21/09/02 13:59	29/09/02 17:03	29.65
06/10/02 11:18	13/10/02 05:33	21/10/02 07:20	29/10/02 05:28	29.72
04/11/02 20:34	11/11/02 20:52	20/11/02 01:34	27/11/02 15:46	29.76
04/12/02 07:34	11/12/02 15:49	19/12/02 19:10	27/12/02 00:31	29.73
02/01/03 20:23	10/01/03 13:15	18/01/03 10:48	25/01/03 08:33	29.65
01/02/03 10:48	09/02/03 11:11	16/02/03 23:51	23/02/03 16:46	29.54
03/03/03 02:35	11/03/03 07:15	18/03/03 10:34	25/03/03 01:51	29.45
01/04/03 19:19	09/04/03 23:40	16/04/03 19:36	23/04/03 12:18	29.38
01/05/03 12:15	09/05/03 11:53	16/05/03 03:36	23/05/03 00:31	29.33
31/05/03 04:20	07/06/03 20:28	14/06/03 11:16	21/06/03 14:45	29.32
29/06/03 18:39	07/07/03 02:32	13/07/03 19:21	21/07/03 07:01	29.34
29/07/03 06:53	05/08/03 07:28	12/08/03 04:48	20/08/03 00:48	29.39
27/08/03 17:26	03/09/03 12:34	10/09/03 16:36	18/09/03 19:03	29.49
26/09/03 03:09	02/10/03 19:09	10/10/03 07:27	18/10/03 12:31	29.62
25/10/03 12:50	01/11/03 04:25	09/11/03 01:13	17/11/03 04:15	29.74
23/11/03 22:59	30/11/03 17:16	08/12/03 20:37	16/12/03 17:42	29.81
23/12/03 09:43	30/12/03 10:03	07/01/04 15:40	15/01/04 04:46	29.79
21/01/04 21:05	29/01/04 06:03	06/02/04 08:47	13/02/04 13:40	29.71
20/02/04 09:18	28/02/04 03:24	06/03/04 23:14	13/03/04 21:01	29.60
20/03/04 22:41	28/03/04 23:48	05/04/04 11:03	12/04/04 03:46	29.49
19/04/04 13:21	27/04/04 17:32	04/05/04 20:33	11/05/04 11:04	29.40
19/05/04 04:52	27/05/04 07:57	03/06/04 04:20	09/06/04 20:02	29.32
17/06/04 20:27	25/06/04 19:08	02/07/04 11:09	09/07/04 07:34	29.28
17/07/04 11:24	25/07/04 03:37	31/07/04 18:05	07/08/04 22:01	29.29
16/08/04 01:24	23/08/04 10:12	30/08/04 02:22	06/09/04 15:11	29.35
14/09/04 14:29	21/09/04 15:54	28/09/04 13:09	06/10/04 10:12	29.45
14/10/04 02:48	20/10/04 21:59	28/10/04 03:07	05/11/04 05:53	29.58
12/11/04 14:27	19/11/04 05:50	26/11/04 20:07	05/12/04 00:53	29.71
12/12/04 01:29	18/12/04 16:40	26/12/04 15:06	03/01/05 17:46	29.79
10/01/05 12:03	17/01/05 06:57	25/01/05 10:32	02/02/05 07:27	29.81
08/02/05 22:28	16/02/05 00:16	24/02/05 04:54	03/03/05 17:36	29.77
10/03/05 09:10	17/03/05 19:19	25/03/05 20:58	02/04/05 00:50	29.67
08/04/05 20:32	16/04/05 14:37	24/04/05 10:06	01/05/05 06:24	29.55
08/05/05 08:45	16/05/05 08:56	23/05/05 20:18	30/05/05 11:47	29.43
06/06/05 21:55	15/06/05 01:22	22/06/05 04:14	28/06/05 18:23	29.33
06/07/05 12:02	14/07/05 15:20	21/07/05 11:00	28/07/05 03:19	29.28
05/08/05 03:05	13/08/05 02:38	19/08/05 17:53	26/08/05 15:18	29.29
03/09/05 18:45	11/09/05 11:37	18/09/05 02:01	25/09/05 06:41	29.34
03/10/05 10:28	10/10/05 19:01	17/10/05 12:14	25/10/05 01:17	29.43
02/11/05 01:24	09/11/05 01:57	16/11/05 00:57	23/11/05 22:11	29.53
01/12/05 15:01	08/12/05 09:36	15/12/05 16:15	23/12/05 19:36	29.64
31/12/05 03:12				

Readers comments

judyfogarty1@comcast.net

judy fogarty Sun Oct 22 2017

I'm really confused, and need to get this right. I'm writing a novel called MOON, which begins on a full moon and ends on one. A full moon is "Day 1" in the novel and the next full moon is "Day 31." Is that because the 29 days are literally between the full moons, with the actual full moon days added to equal 31?

Add a comment/link:

Enter your comment about this page here.

Subject:

 

Links To add a link to another website with useful info add the details here.
Name of Site:
URL for Site:
Details:

Your Name:
email address:
Email addressed added here will not be displayed on the website or be passed to third parties.
They are used incase we need to get in touch with you.
1 + 3 =
Answer the sum to prove your not a robot. As we all know robots can't add.
To prevent spam all comments are moderated, comments with spam or swearing are blocked.


Msqli defined