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: 11-16 (100), 11-17 (100), 11-18 (100), 11-19 (100), 11-20 (100) — by astronomy; check the weather when the night is within four days.

2031-11-16astronomy score per night — click a bar for that night2031-12-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-11-16 Sun	100	—	unknown	18:40–03:30 (good, 8.83 h)	89.5° 21:25	10.98	6%	117.9°
2031-11-17 Mon	100	—	unknown	18:40–03:30 (good, 8.83 h)	89.7° 21:20	11.01	12%	105.9°
2031-11-18 Tue	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.8° 21:15	11.04	21%	93.5°
2031-11-19 Wed	100	—	unknown	18:35–03:20 (good, 8.75 h)	89.7° 21:10	11.06	31%	81.2°
2031-11-20 Thu	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.5° 21:05	11.09	42%	69.2°
2031-11-21 Fri	97	—	unknown	18:35–03:10 (good, 8.58 h)	89.6° 21:05	11.11	54%	57.8°
2031-11-22 Sat	88	—	unknown	18:35–03:10 (good, 8.58 h)	89.7° 21:00	11.14	64%	47.4°
2031-11-23 Sun	81	—	unknown	02:25–03:05 (good, 0.67 h)	89.7° 20:55	11.16	75%	38.7°
2031-11-24 Mon	49	—	unknown	18:35–03:25 (marginal, 8.83 h)	89.6° 20:50	11.19	83%	32.9°
2031-11-25 Tue	34	—	unknown	18:35–03:05 (marginal, 8.5 h)	89.5° 20:45	11.21	90%	31.4°
2031-11-26 Wed	32	—	unknown	18:35–02:40 (marginal, 8.08 h)	89.6° 20:45	11.23	96%	34.7°
2031-11-27 Thu	38	—	unknown	18:35–02:20 (marginal, 7.75 h)	89.7° 20:40	11.25	99%	41.4°
2031-11-28 Fri	51	—	unknown	18:35–02:20 (marginal, 7.75 h)	89.7° 20:35	11.27	100%	50.0°
2031-11-29 Sat	65	—	unknown	18:35–19:40 (good, 1.08 h)	89.6° 20:30	11.29	99%	59.6°
2031-11-30 Sun	74	—	unknown	18:35–21:55 (good, 3.33 h)	89.5° 20:30	11.31	96%	69.5°
2031-12-01 Mon	100	—	unknown	18:35–00:00 (good, 5.42 h)	89.7° 20:25	11.33	92%	79.7°
2031-12-02 Tue	100	—	unknown	18:35–01:20 (good, 6.75 h)	89.8° 20:20	11.34	86%	89.9°
2031-12-03 Wed	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.7° 20:15	11.36	79%	99.9°
2031-12-04 Thu	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.5° 20:10	11.38	70%	109.9°
2031-12-05 Fri	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.6° 20:10	11.39	62%	119.6°
2031-12-06 Sat	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.7° 20:05	11.4	52%	128.9°
2031-12-07 Sun	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.7° 20:00	11.42	42%	137.4°
2031-12-08 Mon	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.6° 19:55	11.43	33%	144.3°
2031-12-09 Tue	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.5° 19:50	11.44	23%	148.3°
2031-12-10 Wed	100	—	unknown	18:35–01:55 (good, 7.33 h)	89.6° 19:50	11.45	15%	147.7°
2031-12-11 Thu	100	—	unknown	18:35–01:55 (good, 7.33 h)	89.7° 19:45	11.46	8%	142.4°
2031-12-12 Fri	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.7° 19:40	11.47	3%	133.6°
2031-12-13 Sat	100	—	unknown	18:35–01:45 (good, 7.17 h)	89.6° 19:35	11.48	0%	122.7°
2031-12-14 Sun	100	—	unknown	18:35–01:40 (good, 7.08 h)	89.5° 19:35	11.48	0%	110.6°
2031-12-15 Mon	100	—	unknown	18:35–01:40 (good, 7.08 h)	89.7° 19:30	11.49	4%	98.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-16&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.