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: 11-27 (100), 11-28 (100), 11-29 (100), 11-30 (100), 12-01 (100) — by astronomy; check the weather when the night is within four days.

2037-11-27astronomy score per night — click a bar for that night2037-12-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-11-27 Fri	100	—	unknown	18:35–02:20 (good, 7.75 h)	89.5° 20:40	11.26	75%	96.3°
2037-11-28 Sat	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.7° 20:35	11.28	65%	106.8°
2037-11-29 Sun	100	—	unknown	18:35–02:30 (good, 7.92 h)	89.8° 20:30	11.3	54%	117.0°
2037-11-30 Mon	100	—	unknown	18:35–02:30 (good, 7.92 h)	89.7° 20:25	11.32	42%	126.6°
2037-12-01 Tue	100	—	unknown	18:35–02:30 (good, 7.92 h)	89.6° 20:20	11.34	31%	134.6°
2037-12-02 Wed	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.6° 20:20	11.35	21%	140.0°
2037-12-03 Thu	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.7° 20:15	11.37	12%	141.5°
2037-12-04 Fri	100	—	unknown	18:35–02:20 (good, 7.75 h)	89.8° 20:10	11.38	6%	138.4°
2037-12-05 Sat	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.7° 20:05	11.4	2%	131.8°
2037-12-06 Sun	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.5° 20:00	11.41	0%	123.1°
2037-12-07 Mon	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.6° 20:00	11.42	1%	113.2°
2037-12-08 Tue	100	—	unknown	18:35–02:05 (good, 7.5 h)	89.8° 19:55	11.44	5%	102.9°
2037-12-09 Wed	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.8° 19:50	11.45	10%	92.5°
2037-12-10 Thu	100	—	unknown	18:35–01:55 (good, 7.33 h)	89.6° 19:45	11.46	17%	82.5°
2037-12-11 Fri	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.5° 19:45	11.47	25%	72.8°
2037-12-12 Sat	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.7° 19:40	11.47	34%	63.7°
2037-12-13 Sun	92	—	unknown	18:35–01:45 (good, 7.17 h)	89.8° 19:35	11.48	44%	55.4°
2037-12-14 Mon	85	—	unknown	18:35–01:40 (good, 7.08 h)	89.7° 19:30	11.49	53%	48.2°
2037-12-15 Tue	71	—	unknown	18:35–01:10 (good, 6.58 h)	89.6° 19:25	11.49	62%	42.6°
2037-12-16 Wed	57	—	unknown	18:35–02:05 (marginal, 7.5 h)	89.6° 19:25	11.5	71%	39.2°
2037-12-17 Thu	45	—	unknown	18:35–01:50 (marginal, 7.25 h)	89.7° 19:20	11.5	79%	38.7°
2037-12-18 Fri	38	—	unknown	18:35–01:30 (marginal, 6.92 h)	89.8° 19:15	11.5	87%	41.3°
2037-12-19 Sat	37	—	unknown	18:35–01:15 (marginal, 6.67 h)	89.7° 19:10	11.51	93%	46.6°
2037-12-20 Sun	42	—	unknown	18:35–01:05 (marginal, 6.5 h)	89.5° 19:05	11.51	97%	54.0°
2037-12-21 Mon	52	—	unknown	18:35–18:45 (good, 0.17 h)	89.6° 19:05	11.51	100%	62.7°
2037-12-22 Tue	67	—	unknown	18:35–20:45 (good, 2.17 h)	89.8° 19:00	11.51	100%	72.5°
2037-12-23 Wed	77	—	unknown	18:40–22:30 (good, 3.83 h)	89.8° 18:55	11.5	98%	82.9°
2037-12-24 Thu	100	—	unknown	18:40–23:50 (good, 5.17 h)	89.6° 18:50	11.5	94%	93.6°
2037-12-25 Fri	100	—	unknown	18:40–00:30 (good, 5.83 h)	89.5° 18:50	11.5	87%	104.3°
2037-12-26 Sat	100	—	unknown	18:40–00:40 (good, 6.0 h)	89.7° 18:45	11.49	78%	114.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-11-27&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.