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: 11-04 (100), 11-05 (100), 11-06 (100), 11-07 (100), 11-08 (100) — by astronomy; check the weather when the night is within four days.

2039-11-03astronomy score per night — click a bar for that night2039-12-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-11-03 Thu	95	—	unknown	18:50–21:10 (good, 2.33 h)	89.7° 22:15	10.57	92%	54.7°
2039-11-04 Fri	100	—	unknown	18:50–23:25 (good, 4.58 h)	89.8° 22:10	10.6	86%	63.2°
2039-11-05 Sat	100	—	unknown	18:50–01:40 (good, 6.83 h)	89.7° 22:05	10.64	79%	72.1°
2039-11-06 Sun	100	—	unknown	18:45–03:00 (good, 8.25 h)	89.5° 22:00	10.67	71%	81.4°
2039-11-07 Mon	100	—	unknown	18:45–03:40 (good, 8.92 h)	89.6° 22:00	10.71	62%	90.9°
2039-11-08 Tue	100	—	unknown	18:45–03:50 (good, 9.08 h)	89.8° 21:55	10.74	52%	100.6°
2039-11-09 Wed	100	—	unknown	18:45–03:50 (good, 9.08 h)	89.8° 21:50	10.77	42%	110.2°
2039-11-10 Thu	100	—	unknown	18:45–03:50 (good, 9.08 h)	89.6° 21:45	10.8	33%	119.7°
2039-11-11 Fri	100	—	unknown	18:45–03:50 (good, 9.08 h)	89.5° 21:45	10.83	23%	128.6°
2039-11-12 Sat	100	—	unknown	18:40–03:45 (good, 9.08 h)	89.7° 21:40	10.87	15%	136.4°
2039-11-13 Sun	100	—	unknown	18:40–03:45 (good, 9.08 h)	89.8° 21:35	10.9	8%	141.6°
2039-11-14 Mon	100	—	unknown	18:40–03:40 (good, 9.0 h)	89.7° 21:30	10.93	3%	142.8°
2039-11-15 Tue	100	—	unknown	18:40–03:35 (good, 8.92 h)	89.6° 21:25	10.95	0%	139.3°
2039-11-16 Wed	100	—	unknown	18:40–03:30 (good, 8.83 h)	89.6° 21:25	10.98	1%	131.8°
2039-11-17 Thu	100	—	unknown	18:40–03:30 (good, 8.83 h)	89.7° 21:20	11.01	4%	122.0°
2039-11-18 Fri	100	—	unknown	18:40–03:25 (good, 8.75 h)	89.8° 21:15	11.04	10%	110.9°
2039-11-19 Sat	100	—	unknown	18:35–03:20 (good, 8.75 h)	89.7° 21:10	11.06	19%	99.4°
2039-11-20 Sun	100	—	unknown	18:35–03:15 (good, 8.67 h)	89.5° 21:05	11.09	29%	87.9°
2039-11-21 Mon	100	—	unknown	18:35–03:10 (good, 8.58 h)	89.6° 21:05	11.12	39%	76.7°
2039-11-22 Tue	100	—	unknown	18:35–03:10 (good, 8.58 h)	89.8° 21:00	11.14	50%	66.2°
2039-11-23 Wed	92	—	unknown	18:35–03:05 (good, 8.5 h)	89.8° 20:55	11.16	61%	56.5°
2039-11-24 Thu	85	—	unknown	18:35–03:00 (good, 8.42 h)	89.6° 20:50	11.19	71%	48.1°
2039-11-25 Fri	63	—	unknown	02:50–02:55 (good, 0.08 h)	89.5° 20:50	11.21	80%	41.6°
2039-11-26 Sat	48	—	unknown	18:35–03:15 (marginal, 8.67 h)	89.7° 20:45	11.23	87%	37.8°
2039-11-27 Sun	40	—	unknown	18:35–02:55 (marginal, 8.33 h)	89.8° 20:40	11.25	93%	37.2°
2039-11-28 Mon	38	—	unknown	18:35–02:30 (marginal, 7.92 h)	89.7° 20:35	11.27	97%	40.0°
2039-11-29 Tue	43	—	unknown	18:35–02:15 (marginal, 7.67 h)	89.6° 20:30	11.29	99%	45.4°
2039-11-30 Wed	54	—	unknown	18:35–02:15 (marginal, 7.67 h)	89.6° 20:30	11.31	100%	52.6°
2039-12-01 Thu	66	—	unknown	18:35–19:50 (good, 1.25 h)	89.7° 20:25	11.33	99%	60.8°
2039-12-02 Fri	74	—	unknown	18:35–21:55 (good, 3.33 h)	89.8° 20:20	11.35	96%	69.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-11-03&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.