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: 10-17 (100), 10-18 (100), 10-19 (100), 10-20 (100), 10-21 (100) — by astronomy; check the weather when the night is within four days.

2044-10-17astronomy score per night — click a bar for that night2044-11-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-10-17 Mon	100	—	unknown	20:10–06:05 (good, 9.92 h)	89.6° 00:20	9.93	11%	129.7°
2044-10-18 Tue	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.8° 00:15	9.98	5%	139.5°
2044-10-19 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	89.8° 00:10	10.02	1%	146.9°
2044-10-20 Thu	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.7° 00:05	10.06	0%	150.4°
2044-10-21 Fri	100	—	unknown	20:05–06:10 (good, 10.08 h)	89.5° 00:00	10.1	1%	148.8°
2044-10-22 Sat	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.7° 00:00	10.14	4%	143.1°
2044-10-23 Sun	100	—	unknown	20:05–06:05 (good, 10.0 h)	89.8° 23:55	10.18	9%	135.0°
2044-10-24 Mon	100	—	unknown	20:00–06:00 (good, 10.0 h)	89.8° 23:50	10.22	15%	125.7°
2044-10-25 Tue	100	—	unknown	20:00–05:55 (good, 9.92 h)	89.6° 23:45	10.26	23%	115.8°
2044-10-26 Wed	100	—	unknown	20:00–05:50 (good, 9.83 h)	89.5° 23:45	10.3	31%	105.7°
2044-10-27 Thu	100	—	unknown	19:55–05:50 (good, 9.92 h)	89.7° 23:40	10.34	40%	95.5°
2044-10-28 Fri	100	—	unknown	19:55–05:45 (good, 9.83 h)	89.8° 23:35	10.38	49%	85.2°
2044-10-29 Sat	100	—	unknown	19:55–04:40 (good, 9.75 h)	89.7° 23:30	10.41	59%	74.8°
2044-10-30 Sun	100	—	unknown	18:55–04:35 (good, 9.67 h)	89.6° 22:25	10.45	68%	64.5°
2044-10-31 Mon	92	—	unknown	19:30–04:30 (good, 9.0 h)	89.6° 22:25	10.49	77%	54.3°
2044-11-01 Tue	84	—	unknown	03:15–04:30 (good, 1.25 h)	89.8° 22:20	10.52	85%	44.6°
2044-11-02 Wed	61	—	unknown	04:20–04:25 (good, 0.08 h)	89.8° 22:15	10.56	92%	36.2°
2044-11-03 Thu	34	—	unknown	23:55–04:25 (marginal, 4.5 h)	89.7° 22:10	10.6	97%	30.6°
2044-11-04 Fri	30	—	unknown	18:50–21:00 (marginal, 2.17 h)	89.5° 22:05	10.63	99%	30.0°
2044-11-05 Sat	38	—	unknown	18:45–22:15 (marginal, 3.5 h)	89.7° 22:05	10.66	100%	35.0°
2044-11-06 Sun	56	—	unknown	18:45–02:20 (marginal, 7.58 h)	89.8° 22:00	10.7	97%	43.9°
2044-11-07 Mon	67	—	unknown	18:45–20:50 (good, 2.08 h)	89.8° 21:55	10.73	92%	55.0°
2044-11-08 Tue	100	—	unknown	18:45–00:20 (good, 5.58 h)	89.6° 21:50	10.76	84%	67.1°
2044-11-09 Wed	100	—	unknown	18:45–02:20 (good, 7.58 h)	89.5° 21:50	10.8	75%	79.5°
2044-11-10 Thu	100	—	unknown	18:45–03:25 (good, 8.67 h)	89.7° 21:45	10.83	65%	92.0°
2044-11-11 Fri	100	—	unknown	18:40–03:35 (good, 8.92 h)	89.8° 21:40	10.86	53%	104.3°
2044-11-12 Sat	100	—	unknown	18:40–03:40 (good, 9.0 h)	89.7° 21:35	10.89	42%	116.1°
2044-11-13 Sun	100	—	unknown	18:40–03:40 (good, 9.0 h)	89.6° 21:30	10.92	32%	127.3°
2044-11-14 Mon	100	—	unknown	18:40–03:35 (good, 8.92 h)	89.6° 21:30	10.95	22%	137.3°
2044-11-15 Tue	100	—	unknown	18:40–03:35 (good, 8.92 h)	89.8° 21:25	10.98	14%	145.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-10-17&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.