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: 07-23 (100), 07-24 (100), 07-25 (100), 07-26 (100), 07-27 (100) — by astronomy; check the weather when the night is within four days.

2044-07-23astronomy score per night — click a bar for that night2044-08-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-07-23 Sat	100	—	unknown	23:50–04:10 (good, 4.33 h)	89.7° 05:55	5.4	1%	81.8°
2044-07-24 Sun	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.5° 05:50	5.45	0%	94.9°
2044-07-25 Mon	100	—	unknown	23:45–04:15 (good, 4.5 h)	89.7° 05:50	5.51	2%	107.8°
2044-07-26 Tue	100	—	unknown	23:40–04:15 (good, 4.58 h)	89.8° 05:45	5.56	7%	120.1°
2044-07-27 Wed	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.8° 05:40	5.61	14%	131.3°
2044-07-28 Thu	100	—	unknown	23:35–04:20 (good, 4.75 h)	89.6° 05:35	5.67	22%	140.9°
2044-07-29 Fri	100	—	unknown	23:30–04:20 (good, 4.83 h)	89.5° 05:35	5.72	32%	147.8°
2044-07-30 Sat	100	—	unknown	23:30–04:25 (good, 4.92 h)	89.7° 05:30	5.77	42%	150.5°
2044-07-31 Sun	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.8° 05:25	5.83	52%	148.5°
2044-08-01 Mon	100	—	unknown	23:25–04:25 (good, 5.0 h)	89.8° 05:20	5.88	62%	142.7°
2044-08-02 Tue	100	—	unknown	23:20–04:30 (good, 5.17 h)	89.6° 05:15	5.94	71%	134.8°
2044-08-03 Wed	100	—	unknown	23:15–04:30 (good, 5.25 h)	89.6° 05:15	5.99	79%	125.8°
2044-08-04 Thu	100	—	unknown	23:15–04:30 (good, 5.25 h)	89.8° 05:10	6.05	86%	116.1°
2044-08-05 Fri	100	—	unknown	23:20–04:35 (good, 5.25 h)	89.8° 05:05	6.11	92%	106.1°
2044-08-06 Sat	100	—	unknown	23:25–04:35 (good, 5.17 h)	89.7° 05:00	6.16	96%	95.8°
2044-08-07 Sun	77	—	unknown	00:00–04:35 (good, 4.58 h)	89.5° 04:55	6.22	99%	85.3°
2044-08-08 Mon	69	—	unknown	01:20–04:40 (good, 3.33 h)	89.6° 04:55	6.28	100%	74.9°
2044-08-09 Tue	54	—	unknown	22:20–05:20 (marginal, 7.0 h)	89.8° 04:50	6.33	99%	64.4°
2044-08-10 Wed	43	—	unknown	22:20–04:40 (marginal, 6.33 h)	89.8° 04:45	6.39	96%	54.2°
2044-08-11 Thu	38	—	unknown	22:15–04:40 (marginal, 6.42 h)	89.7° 04:40	6.45	91%	44.6°
2044-08-12 Fri	39	—	unknown	22:15–04:45 (marginal, 6.5 h)	89.5° 04:40	6.51	84%	36.4°
2044-08-13 Sat	48	—	unknown	22:10–04:45 (marginal, 6.58 h)	89.7° 04:35	6.56	76%	30.8°
2044-08-14 Sun	74	—	unknown	22:25–22:50 (good, 0.42 h)	89.8° 04:30	6.62	66%	29.7°
2044-08-15 Mon	83	—	unknown	22:20–04:50 (good, 6.5 h)	89.8° 04:25	6.68	55%	33.9°
2044-08-16 Tue	87	—	unknown	22:20–04:50 (good, 6.5 h)	89.6° 04:20	6.74	44%	42.0°
2044-08-17 Wed	93	—	unknown	22:15–04:50 (good, 6.58 h)	89.6° 04:20	6.79	33%	52.4°
2044-08-18 Thu	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.7° 04:15	6.85	22%	64.2°
2044-08-19 Fri	100	—	unknown	22:05–04:55 (good, 6.83 h)	89.8° 04:10	6.91	13%	76.6°
2044-08-20 Sat	100	—	unknown	22:00–04:55 (good, 6.92 h)	89.7° 04:05	6.97	6%	89.5°
2044-08-21 Sun	100	—	unknown	22:00–04:55 (good, 6.92 h)	89.5° 04:00	7.02	2%	102.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-07-23&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.