Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Andromeda Galaxy: 12-30 (100), 12-31 (100), 01-01 (100), 01-02 (100), 01-03 (100) — by astronomy; check the weather when the night is within four days.

2042-12-30astronomy score per night — click a bar for that night2043-01-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-12-30 Tue	100	—	unknown	18:40–00:25 (good, 5.75 h)	89.8° 18:30	11.47	80%	115.9°
2042-12-31 Wed	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.8° 18:25	11.46	72%	125.8°
2043-01-01 Thu	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.7° 18:20	11.45	62%	134.6°
2043-01-02 Fri	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.5° 18:15	11.44	53%	141.8°
2043-01-03 Sat	100	—	unknown	18:45–00:20 (good, 5.58 h)	89.6° 18:15	11.43	44%	146.6°
2043-01-04 Sun	100	—	unknown	18:45–00:20 (good, 5.58 h)	89.8° 18:10	11.42	34%	148.0°
2043-01-05 Mon	100	—	unknown	18:45–00:15 (good, 5.5 h)	89.8° 18:05	11.4	26%	145.6°
2043-01-06 Tue	100	—	unknown	18:50–00:10 (good, 5.33 h)	89.6° 18:00	11.39	18%	140.0°
2043-01-07 Wed	100	—	unknown	18:50–00:05 (good, 5.25 h)	89.5° 18:00	11.38	11%	132.2°
2043-01-08 Thu	100	—	unknown	18:50–00:05 (good, 5.25 h)	89.7° 17:55	11.36	6%	123.1°
2043-01-09 Fri	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 17:50	11.34	2%	113.0°
2043-01-10 Sat	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.7° 17:45	11.33	0%	102.3°
2043-01-11 Sun	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.6° 17:40	11.31	1%	91.2°
2043-01-12 Mon	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.6° 17:40	11.29	3%	79.9°
2043-01-13 Tue	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.7° 17:35	11.27	8%	68.6°
2043-01-14 Wed	96	—	unknown	18:55–23:40 (good, 4.75 h)	89.8° 17:30	11.25	15%	57.5°
2043-01-15 Thu	89	—	unknown	18:55–23:35 (good, 4.67 h)	89.7° 17:25	11.23	24%	47.2°
2043-01-16 Fri	81	—	unknown	18:55–23:30 (good, 4.58 h)	89.5° 17:20	11.21	34%	38.5°
2043-01-17 Sat	60	—	unknown	19:00–23:00 (good, 4.0 h)	89.6° 17:20	11.18	45%	32.9°
2043-01-18 Sun	42	—	unknown	19:00–23:55 (marginal, 4.92 h)	89.8° 17:15	11.16	56%	32.2°
2043-01-19 Mon	31	—	unknown	19:00–23:35 (marginal, 4.58 h)	89.8° 17:10	11.14	67%	36.7°
2043-01-20 Tue	26	—	unknown	19:00–23:20 (marginal, 4.33 h)	89.6° 17:05	11.11	78%	44.9°
2043-01-21 Wed	26	—	unknown	19:00–23:10 (marginal, 4.17 h)	89.5° 17:05	11.09	86%	55.1°
2043-01-22 Thu	31	—	unknown	19:05–23:10 (marginal, 4.08 h)	89.7° 17:00	11.06	93%	66.3°
2043-01-23 Fri	40	—	unknown	19:05–19:55 (good, 0.83 h)	89.8° 16:55	11.03	98%	77.9°
2043-01-24 Sat	51	—	unknown	19:05–21:05 (good, 2.0 h)	89.8° 16:50	11.0	100%	89.5°
2043-01-25 Sun	64	—	unknown	19:05–22:20 (good, 3.25 h)	89.6° 16:45	10.98	99%	101.0°
2043-01-26 Mon	76	—	unknown	19:05–22:30 (good, 3.42 h)	89.6° 16:45	10.95	97%	112.0°
2043-01-27 Tue	90	—	unknown	19:10–22:35 (good, 3.42 h)	89.7° 16:40	10.92	92%	122.3°
2043-01-28 Wed	90	—	unknown	19:10–22:35 (good, 3.42 h)	89.8° 16:35	10.89	86%	131.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-12-30&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.