KECK OBSERVATORY CALENDAR FOR 2025 -ASTRONOMICAL (computed for altitude 4160.0 m) ASTRONOMICAL(18 deg) TWILIGHT/DAWN MOON(midnight) DATE(HST) SUN TWILIGHT ENDS MOON MOON DAWN BEGINS SUN SIDEREAL TIMES NIGHT (18 deg) Zenith 2025 SET RISE SET RISE TWI MID DAWN LENGTH DARK___ RA DEC Dist 12 18 18 12 18 18 h h % h m d m deg FRI AUG 01 19 10 19 50 20 19 00 19 04 38 05 06 05 47 16 41 20 23 01 02 8.3 4.3 51 1503-2218 89 SAT AUG 02 19 09 19 50 20 18 01 01 04 39 05 07 05 47 16 44 20 27 01 07 8.4 3.6 43 1552-2547 81 SUN AUG 03 19 09 19 49 20 17 14 28 01 48 04 39 05 07 05 48 16 47 20 31 01 11 8.4 2.9 34 1645-2809 73 MON AUG 04 19 08 19 48 20 17 15 23 02 40 04 40 05 08 05 48 16 51 20 35 01 16 8.4 2.0 23 1741-2908 65 TUE AUG 05 19 07 19 48 20 16 16 17 03 36 04 40 05 08 05 48 16 54 20 39 01 20 8.4 1.1 12 1838-2840 57 WED AUG 06 19 07 19 47 20 15 17 10 04 35 04 41 05 09 05 49 16 57 20 43 01 25 8.4 0.1 1 1936-2641 49 THU AUG 07 19 06 19 46 20 14 17 58 05 34 04 41 05 09 05 49 17 00 20 47 01 29 8.4 0.0 0 2032-2314 43 FRI AUG 08 19 06 19 46 20 14 18 43 06 33 04 42 05 09 05 50 17 04 20 51 01 33 8.5 0.0 0 2126-1830 39 SAT AUG 09 19 05 19 45 20 13 19 23 04 42 05 10 05 50 17 07 20 55 01 37 8.5 0.0 0 2219-1245 39 SUN AUG 10 19 05 19 44 20 12 20 02 04 43 05 10 05 50 17 10 20 59 01 42 8.5 0.0 0 2309-0619 41 MON AUG 11 19 04 19 44 20 11 20 39 04 43 05 11 05 51 17 13 21 03 01 46 8.5 0.5 5 2400 0028 47 TUE AUG 12 19 03 19 43 20 11 21 16 04 44 05 11 05 51 17 17 21 06 01 51 8.6 1.1 12 0050 0714 56 WED AUG 13 19 03 19 42 20 10 21 55 04 44 05 12 05 51 17 20 21 10 01 55 8.6 1.8 20 0142 1337 65 THU AUG 14 19 02 19 41 20 09 22 37 04 44 05 12 05 51 17 23 21 14 01 59 8.6 2.5 28 0237 1914 75 FRI AUG 15 19 01 19 41 20 08 23 24 04 45 05 12 05 52 17 26 21 18 02 04 8.6 3.3 37 0335 2341 86 SAT AUG 16 19 01 19 40 20 07 00 18 04 45 05 13 05 52 17 29 21 22 02 08 8.6 4.2 48 0436 2645 >90 SUN AUG 17 19 00 19 39 20 06 01 16 14 42 04 46 05 13 05 52 17 32 21 26 02 13 8.7 5.2 59 0539 2801 >90 MON AUG 18 18 59 19 38 20 06 02 19 15 44 04 46 05 13 05 53 17 35 21 30 02 17 8.7 6.2 71 0642 2728 >90 TUE AUG 19 18 58 19 37 20 05 03 24 16 41 04 47 05 14 05 53 17 38 21 34 02 22 8.7 7.3 84 0742 2514 >90 WED AUG 20 18 58 19 37 20 04 04 26 17 31 04 47 05 14 05 53 17 41 21 38 02 26 8.7 8.4 95 0838 2134 >90 THU AUG 21 18 57 19 36 20 03 05 25 18 15 04 48 05 15 05 54 17 44 21 42 02 31 8.8 8.8 100 0931 1652 >90 FRI AUG 22 18 56 19 35 20 02 06 20 18 53 04 48 05 15 05 54 17 47 21 46 02 35 8.8 8.8 100 1019 1127 >90 SAT AUG 23 18 55 19 34 20 01 19 28 04 48 05 15 05 54 17 50 21 50 02 39 8.8 8.8 100 1105 0539 >90 SUN AUG 24 18 54 19 33 20 00 20 01 04 49 05 16 05 54 17 53 21 54 02 44 8.8 8.8 99 1149-0016 >90 MON AUG 25 18 54 19 32 19 59 20 33 04 49 05 16 05 55 17 56 21 58 02 48 8.8 8.3 93 1232-0605 >90 TUE AUG 26 18 53 19 32 19 58 21 05 04 49 05 16 05 55 17 59 22 02 02 51 8.8 7.7 87 1315-1136 >90 WED AUG 27 18 52 19 31 19 57 21 39 04 50 05 16 05 55 18 02 22 06 02 56 8.9 7.2 80 1359-1640 >90 THU AUG 28 18 51 19 30 19 56 22 15 04 50 05 17 05 55 18 05 22 10 03 00 8.9 6.6 73 1445-2106 >90 FRI AUG 29 18 50 19 29 19 55 22 55 04 51 05 17 05 56 18 08 22 13 03 05 8.9 5.9 66 1534-2445 >90 SAT AUG 30 18 50 19 28 19 54 23 40 04 51 05 17 05 56 18 11 22 17 03 09 9.0 5.2 57 1626-2723 >90 SUN AUG 31 18 49 19 27 19 53 00 29 04 51 05 18 05 56 18 14 22 21 03 13 9.0 4.4 48 1721-2843 88 ONE LINE REFERS TO EVENING DATE FIRST QUARTER Aug 01 12:42 UT AND FOLLOWING MORNING. FULL MOON Aug 09 07:54 UT All dates and times are zone HST LAST QUARTER Aug 16 05:13 UT in upper table (except sid time). NEW MOON Aug 23 06:04 UT FIRST QUARTER Aug 31 06:25 UT