2009 Dark Sky Calender
Number of hours of dark skies for N41 Lat W111 Lon for 24 hour period
Day starts at 4 UTC; Sun alt < -9°, Moon alt < -1°

Day | Month>	1	2	3	4	5	6	7	8	9	10	11	12	Total
1	9	7	8	4	3	3	4	3	2	2	1	0	46
2	9	6	7	3	2	3	3	2	1	1	0	0	37
3	8	4	5	3	2	2	3	1	0	0	0	1	29
4	7	3	4	2	2	2	2	0	0	0	0	2	24
5	6	2	3	1	1	1	1	0	0	0	1	3	19
6	4	1	2	1	1	1	0	0	0	0	2	3	15
7	3	0	2	1	0	0	0	0	0	1	2	5	14
8	2	0	1	0	0	0	0	0	1	2	3	6	15
9	1	0	1	0	0	1	0	0	1	2	6	7	19
10	0	1	0	1	0	1	1	0	1	3	7	8	23
11	0	2	0	1	1	2	1	1	2	4	8	9	31
12	1	2	1	2	2	2	2	1	3	6	9	10	41
13	2	3	1	3	3	3	2	2	4	7	10	12	52
14	2	5	2	4	3	3	2	2	5	8	11	13	60
15	3	6	3	5	4	3	3	3	7	9	13	13	72
16	5	7	4	6	4	4	3	4	8	10	13	13	81
17	6	8	5	6	5	4	4	5	9	11	13	12	88
18	7	9	6	7	5	5	5	7	10	11	12	11	95
19	8	10	7	7	5	5	5	8	10	11	11	10	97
20	9	10	8	8	6	6	7	8	10	11	10	10	103
21	10	11	8	8	6	7	8	8	10	11	10	9	106
22	11	11	9	7	7	8	8	8	9	10	9	9	106
23	12	12	9	8	7	8	8	9	9	10	8	8	108
24	12	12	10	8	8	7	7	9	8	9	7	7	104
25	12	11	10	8	8	6	7	8	8	8	6	6	98
26	12	10	10	8	7	6	7	8	7	7	5	5	92
27	11	10	9	7	6	5	6	7	6	6	4	4	81
28	10	9	9	5	5	5	6	6	5	5	3	3	71
29	10		8	4	4	5	5	5	4	4	2	2	53
30	9		6	4	4	4	5	4	3	3	1	0	43
31	8		5		3		4	3		2		0	25
Total	209	172	163	132	114	112	119	122	143	174	187	201	1848