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: 10-20 (100), 10-21 (100), 10-22 (100), 10-23 (100), 11-01 (100) — by astronomy; check the weather when the night is within four days.

2042-10-20astronomy score per night — click a bar for that night2042-11-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-10-20 Mon	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.6° 00:10	10.04	38%	105.0°
2042-10-21 Tue	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.8° 00:05	10.08	48%	94.2°
2042-10-22 Wed	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.8° 00:00	10.12	58%	83.1°
2042-10-23 Thu	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.7° 23:55	10.16	69%	71.7°
2042-10-24 Fri	96	—	unknown	20:05–06:00 (good, 9.92 h)	89.5° 23:55	10.2	79%	60.3°
2042-10-25 Sat	86	—	unknown	02:15–05:00 (good, 3.75 h)	89.7° 23:50	10.24	88%	49.3°
2042-10-26 Sun	64	—	unknown	04:45–04:55 (good, 0.17 h)	89.8° 22:45	10.28	94%	39.8°
2042-10-27 Mon	39	—	unknown	23:35–04:55 (marginal, 5.33 h)	89.8° 22:40	10.32	99%	33.5°
2042-10-28 Tue	37	—	unknown	18:55–22:10 (marginal, 3.25 h)	89.6° 22:35	10.36	100%	32.8°
2042-10-29 Wed	48	—	unknown	18:55–00:20 (marginal, 5.42 h)	89.6° 22:35	10.4	98%	37.9°
2042-10-30 Thu	61	—	unknown	18:55–19:50 (good, 0.92 h)	89.7° 22:30	10.43	93%	46.9°
2042-10-31 Fri	95	—	unknown	18:55–22:25 (good, 3.5 h)	89.8° 22:25	10.47	86%	57.6°
2042-11-01 Sat	100	—	unknown	18:50–01:40 (good, 6.83 h)	89.7° 22:20	10.51	78%	68.9°
2042-11-02 Sun	100	—	unknown	18:50–03:20 (good, 8.5 h)	89.5° 22:15	10.54	68%	80.2°
2042-11-03 Mon	100	—	unknown	18:50–04:00 (good, 9.17 h)	89.6° 22:15	10.58	58%	91.4°
2042-11-04 Tue	100	—	unknown	18:50–04:05 (good, 9.25 h)	89.8° 22:10	10.61	47%	102.1°
2042-11-05 Wed	100	—	unknown	18:50–04:10 (good, 9.33 h)	89.8° 22:05	10.65	38%	112.4°
2042-11-06 Thu	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.7° 22:00	10.68	28%	122.2°
2042-11-07 Fri	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.5° 22:00	10.71	20%	131.1°
2042-11-08 Sat	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.7° 21:55	10.75	13%	138.8°
2042-11-09 Sun	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.8° 21:50	10.78	8%	144.6°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-10-20&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.