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: 11-10 (100), 11-11 (100), 11-12 (100), 11-13 (100), 11-14 (100) — by astronomy; check the weather when the night is within four days.

2042-11-10astronomy score per night — click a bar for that night2042-12-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-11-10 Mon	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.8° 21:45	10.81	3%	147.6°
2042-11-11 Tue	100	—	unknown	18:45–03:50 (good, 9.08 h)	89.6° 21:40	10.84	1%	146.7°
2042-11-12 Wed	100	—	unknown	18:40–03:45 (good, 9.08 h)	89.6° 21:40	10.87	0%	142.4°
2042-11-13 Thu	100	—	unknown	18:40–03:45 (good, 9.08 h)	89.7° 21:35	10.9	1%	135.6°
2042-11-14 Fri	100	—	unknown	18:40–03:40 (good, 9.0 h)	89.8° 21:30	10.93	4%	127.1°
2042-11-15 Sat	100	—	unknown	18:40–03:35 (good, 8.92 h)	89.7° 21:25	10.96	9%	117.6°
2042-11-16 Sun	100	—	unknown	18:40–03:30 (good, 8.83 h)	89.6° 21:20	10.99	15%	107.4°
2042-11-17 Mon	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.6° 21:20	11.02	23%	96.8°
2042-11-18 Tue	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.8° 21:15	11.05	32%	85.9°
2042-11-19 Wed	100	—	unknown	18:35–03:20 (good, 8.75 h)	89.8° 21:10	11.07	43%	74.9°
2042-11-20 Thu	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.7° 21:05	11.1	54%	63.8°
2042-11-21 Fri	90	—	unknown	18:35–03:10 (good, 8.58 h)	89.5° 21:00	11.12	64%	53.0°
2042-11-22 Sat	81	—	unknown	23:15–03:05 (good, 3.83 h)	89.7° 21:00	11.15	75%	43.1°
2042-11-23 Sun	49	—	unknown	18:35–03:30 (marginal, 8.92 h)	89.8° 20:55	11.17	84%	35.5°
2042-11-24 Mon	34	—	unknown	18:35–03:05 (marginal, 8.5 h)	89.8° 20:50	11.19	92%	32.2°
2042-11-25 Tue	31	—	unknown	18:35–21:35 (marginal, 3.0 h)	89.6° 20:45	11.22	97%	34.9°
2042-11-26 Wed	38	—	unknown	18:35–23:50 (marginal, 5.25 h)	89.5° 20:45	11.24	100%	42.4°
2042-11-27 Thu	56	—	unknown	18:35–02:20 (marginal, 7.75 h)	89.7° 20:40	11.26	99%	52.6°
2042-11-28 Fri	70	—	unknown	18:35–20:50 (good, 2.25 h)	89.8° 20:35	11.28	96%	63.9°
2042-11-29 Sat	100	—	unknown	18:35–23:45 (good, 5.17 h)	89.7° 20:30	11.3	90%	75.6°
2042-11-30 Sun	100	—	unknown	18:35–01:20 (good, 6.75 h)	89.6° 20:25	11.32	83%	87.3°
2042-12-01 Mon	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.6° 20:25	11.33	74%	98.5°
2042-12-02 Tue	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.8° 20:20	11.35	64%	109.3°
2042-12-03 Wed	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.8° 20:15	11.37	55%	119.4°
2042-12-04 Thu	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.7° 20:10	11.38	45%	128.8°
2042-12-05 Fri	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.5° 20:05	11.4	36%	137.0°
2042-12-06 Sat	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.7° 20:05	11.41	27%	143.4°
2042-12-07 Sun	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.8° 20:00	11.42	19%	147.2°
2042-12-08 Mon	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.8° 19:55	11.43	12%	147.4°
2042-12-09 Tue	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.6° 19:50	11.44	7%	144.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-11-10&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.