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: 11-12 (100), 11-13 (100), 11-14 (100), 11-15 (100), 11-16 (100) — by astronomy; check the weather when the night is within four days.

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

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2039-12-03 Sat	100	—	unknown	18:35–23:50 (good, 5.25 h)	89.7° 20:15	11.36	91%	78.8°
2039-12-04 Sun	100	—	unknown	18:35–01:05 (good, 6.5 h)	89.5° 20:10	11.38	85%	88.3°
2039-12-05 Mon	100	—	unknown	18:35–01:50 (good, 7.25 h)	89.6° 20:10	11.39	77%	97.8°
2039-12-06 Tue	100	—	unknown	18:35–01:55 (good, 7.33 h)	89.8° 20:05	11.41	69%	107.3°
2039-12-07 Wed	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.8° 20:00	11.42	59%	116.7°
2039-12-08 Thu	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.6° 19:55	11.43	49%	125.6°
2039-12-09 Fri	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.5° 19:55	11.44	39%	133.6°
2039-12-10 Sat	100	—	unknown	18:35–02:00 (good, 7.42 h)	89.7° 19:50	11.45	29%	139.8°
2039-12-11 Sun	100	—	unknown	18:35–01:55 (good, 7.33 h)	89.8° 19:45	11.46	19%	142.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-11-12&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.