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: 10-11 (100), 10-12 (100), 10-13 (100), 10-14 (100), 10-15 (100) — by astronomy; check the weather when the night is within four days.

2037-10-11astronomy score per night — click a bar for that night2037-11-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-10-11 Sun	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.5° 00:45	9.66	11%	132.8°
2037-10-12 Mon	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.7° 00:40	9.7	20%	124.2°
2037-10-13 Tue	100	—	unknown	20:15–06:00 (good, 9.75 h)	89.8° 00:35	9.75	29%	114.7°
2037-10-14 Wed	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.7° 00:30	9.79	39%	104.8°
2037-10-15 Thu	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:25	9.84	49%	94.9°
2037-10-16 Fri	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:25	9.88	59%	85.1°
2037-10-17 Sat	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.7° 00:20	9.92	68%	75.7°
2037-10-18 Sun	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.8° 00:15	9.96	77%	66.7°
2037-10-19 Mon	94	—	unknown	22:40–06:10 (good, 7.5 h)	89.7° 00:10	10.01	84%	58.2°
2037-10-20 Tue	87	—	unknown	02:35–06:10 (good, 3.58 h)	89.5° 00:05	10.05	90%	50.6°
2037-10-21 Wed	79	—	unknown	05:40–06:10 (good, 0.5 h)	89.6° 00:05	10.09	95%	44.3°
2037-10-22 Thu	47	—	unknown	20:05–06:10 (marginal, 10.08 h)	89.7° 00:00	10.13	98%	40.0°
2037-10-23 Fri	49	—	unknown	20:05–06:10 (marginal, 10.08 h)	89.8° 23:55	10.17	100%	38.3°
2037-10-24 Sat	53	—	unknown	20:00–04:50 (marginal, 9.83 h)	89.7° 23:50	10.21	99%	39.8°
2037-10-25 Sun	58	—	unknown	19:00–04:45 (marginal, 9.75 h)	89.5° 22:50	10.25	97%	44.2°
2037-10-26 Mon	93	—	unknown	19:00–20:55 (good, 1.92 h)	89.7° 22:45	10.29	93%	50.8°
2037-10-27 Tue	98	—	unknown	19:00–22:55 (good, 3.92 h)	89.8° 22:40	10.33	87%	58.9°
2037-10-28 Wed	100	—	unknown	18:55–01:45 (good, 6.83 h)	89.7° 22:35	10.37	79%	68.0°
2037-10-29 Thu	100	—	unknown	18:55–03:15 (good, 8.33 h)	89.6° 22:30	10.4	70%	77.9°
2037-10-30 Fri	100	—	unknown	18:55–04:10 (good, 9.25 h)	89.5° 22:30	10.44	60%	88.2°
2037-10-31 Sat	100	—	unknown	18:55–04:15 (good, 9.33 h)	89.7° 22:25	10.48	50%	98.8°
2037-11-01 Sun	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.8° 22:20	10.51	38%	109.4°
2037-11-02 Mon	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.7° 22:15	10.55	28%	119.8°
2037-11-03 Tue	100	—	unknown	18:50–04:20 (good, 9.5 h)	89.5° 22:10	10.58	18%	129.2°
2037-11-04 Wed	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.6° 22:10	10.62	10%	136.9°
2037-11-05 Thu	100	—	unknown	18:50–04:15 (good, 9.42 h)	89.7° 22:05	10.65	4%	141.2°
2037-11-06 Fri	100	—	unknown	18:45–04:10 (good, 9.42 h)	89.8° 22:00	10.69	1%	140.9°
2037-11-07 Sat	100	—	unknown	18:45–04:05 (good, 9.33 h)	89.7° 21:55	10.72	0%	136.1°
2037-11-08 Sun	100	—	unknown	18:45–04:00 (good, 9.25 h)	89.5° 21:50	10.75	3%	128.3°
2037-11-09 Mon	100	—	unknown	18:45–03:55 (good, 9.17 h)	89.7° 21:50	10.79	8%	118.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-10-11&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.