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: 10-13 (100), 10-14 (100), 10-15 (100), 10-16 (100), 10-17 (100) — by astronomy; check the weather when the night is within four days.

2047-10-13astronomy score per night — click a bar for that night2047-11-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-10-13 Sun	100	—	unknown	20:20–06:00 (good, 9.67 h)	89.6° 00:35	9.73	33%	102.3°
2047-10-14 Mon	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.6° 00:35	9.77	23%	113.9°
2047-10-15 Tue	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.8° 00:30	9.82	14%	125.4°
2047-10-16 Wed	100	—	unknown	20:15–06:05 (good, 9.83 h)	89.8° 00:25	9.86	7%	136.4°
2047-10-17 Thu	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.7° 00:20	9.9	2%	145.8°
2047-10-18 Fri	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.5° 00:15	9.95	0%	151.1°
2047-10-19 Sat	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.6° 00:15	9.99	1%	149.8°
2047-10-20 Sun	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.8° 00:10	10.03	5%	142.4°
2047-10-21 Mon	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.8° 00:05	10.07	11%	131.8°
2047-10-22 Tue	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.7° 00:00	10.11	20%	120.0°
2047-10-23 Wed	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.5° 00:00	10.15	30%	107.7°
2047-10-24 Thu	100	—	unknown	20:00–06:05 (good, 10.08 h)	89.7° 23:55	10.19	40%	95.6°
2047-10-25 Fri	100	—	unknown	20:00–06:00 (good, 10.0 h)	89.8° 23:50	10.23	51%	83.8°
2047-10-26 Sat	100	—	unknown	20:00–04:55 (good, 9.92 h)	89.8° 23:45	10.27	62%	72.4°
2047-10-27 Sun	99	—	unknown	19:00–04:50 (good, 9.83 h)	89.6° 22:40	10.31	71%	61.5°
2047-10-28 Mon	91	—	unknown	23:15–04:45 (good, 5.5 h)	89.6° 22:40	10.35	80%	51.2°
2047-10-29 Tue	84	—	unknown	03:35–04:45 (good, 1.17 h)	89.8° 22:35	10.39	87%	42.0°
2047-10-30 Wed	61	—	unknown	04:35–04:40 (good, 0.08 h)	89.8° 22:30	10.42	93%	34.4°
2047-10-31 Thu	35	—	unknown	00:15–04:45 (marginal, 4.5 h)	89.7° 22:25	10.46	97%	29.6°
2047-11-01 Fri	31	—	unknown	18:50–21:00 (marginal, 2.17 h)	89.6° 22:20	10.5	99%	28.8°
2047-11-02 Sat	35	—	unknown	18:50–21:45 (marginal, 2.92 h)	89.6° 22:20	10.53	100%	32.3°
2047-11-03 Sun	47	—	unknown	18:50–00:10 (marginal, 5.33 h)	89.8° 22:15	10.57	99%	38.9°
2047-11-04 Mon	60	—	unknown	18:50–19:20 (good, 0.5 h)	89.8° 22:10	10.61	96%	47.3°
2047-11-05 Tue	69	—	unknown	18:50–21:25 (good, 2.58 h)	89.7° 22:05	10.64	91%	56.7°
2047-11-06 Wed	100	—	unknown	18:45–00:20 (good, 5.58 h)	89.5° 22:05	10.67	85%	66.7°
2047-11-07 Thu	100	—	unknown	18:45–02:10 (good, 7.42 h)	89.7° 22:00	10.71	77%	77.2°
2047-11-08 Fri	100	—	unknown	18:45–03:30 (good, 8.75 h)	89.8° 21:55	10.74	69%	87.9°
2047-11-09 Sat	100	—	unknown	18:45–03:40 (good, 8.92 h)	89.8° 21:50	10.77	59%	98.9°
2047-11-10 Sun	100	—	unknown	18:45–03:45 (good, 9.0 h)	89.6° 21:45	10.81	49%	110.0°
2047-11-11 Mon	100	—	unknown	18:45–03:45 (good, 9.0 h)	89.6° 21:45	10.84	38%	121.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-10-13&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.