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

2045-10-10astronomy score per night — click a bar for that night2045-11-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-10-10 Tue	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.6° 00:45	9.62	0%	151.0°
2045-10-11 Wed	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.5° 00:45	9.66	3%	149.8°
2045-10-12 Thu	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.7° 00:40	9.71	8%	143.5°
2045-10-13 Fri	100	—	unknown	20:15–06:00 (good, 9.75 h)	89.8° 00:35	9.75	15%	134.4°
2045-10-14 Sat	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.7° 00:30	9.79	23%	124.2°
2045-10-15 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:25	9.84	32%	113.6°
2045-10-16 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:25	9.88	42%	102.9°
2045-10-17 Tue	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.8° 00:20	9.92	51%	92.4°
2045-10-18 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.8° 00:15	9.97	61%	81.9°
2045-10-19 Thu	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.7° 00:10	10.01	70%	71.6°
2045-10-20 Fri	99	—	unknown	20:25–06:10 (good, 9.75 h)	89.5° 00:05	10.05	78%	61.5°
2045-10-21 Sat	90	—	unknown	01:20–06:10 (good, 4.83 h)	89.7° 00:05	10.09	85%	51.8°
2045-10-22 Sun	83	—	unknown	05:05–06:10 (good, 1.08 h)	89.8° 00:00	10.13	91%	42.7°
2045-10-23 Mon	58	—	unknown	20:05–06:15 (marginal, 10.17 h)	89.8° 23:55	10.17	96%	34.9°
2045-10-24 Tue	33	—	unknown	02:20–06:05 (marginal, 3.75 h)	89.6° 23:50	10.21	99%	29.8°
2045-10-25 Wed	32	—	unknown	20:00–22:30 (marginal, 2.5 h)	89.5° 23:50	10.25	100%	29.0°
2045-10-26 Thu	39	—	unknown	20:00–23:35 (marginal, 3.58 h)	89.7° 23:45	10.29	99%	33.1°
2045-10-27 Fri	55	—	unknown	20:00–03:50 (marginal, 7.83 h)	89.8° 23:40	10.33	95%	40.8°
2045-10-28 Sat	65	—	unknown	19:55–21:55 (good, 2.0 h)	89.8° 23:35	10.37	90%	50.6°
2045-10-29 Sun	98	—	unknown	18:55–23:55 (good, 5.0 h)	89.6° 22:30	10.41	82%	61.6°
2045-10-30 Mon	100	—	unknown	18:55–02:30 (good, 7.58 h)	89.6° 22:30	10.44	73%	73.3°
2045-10-31 Tue	100	—	unknown	18:55–04:05 (good, 9.17 h)	89.8° 22:25	10.48	63%	85.4°
2045-11-01 Wed	100	—	unknown	18:50–04:10 (good, 9.33 h)	89.8° 22:20	10.52	52%	97.6°
2045-11-02 Thu	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.7° 22:15	10.55	41%	109.9°
2045-11-03 Fri	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.5° 22:10	10.59	30%	121.9°
2045-11-04 Sat	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.7° 22:10	10.62	20%	133.3°
2045-11-05 Sun	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.8° 22:05	10.66	11%	143.1°
2045-11-06 Mon	100	—	unknown	18:45–04:10 (good, 9.42 h)	89.8° 22:00	10.69	5%	149.8°
2045-11-07 Tue	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.7° 21:55	10.72	1%	151.1°
2045-11-08 Wed	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.5° 21:55	10.76	0%	146.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-10-10&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.