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: 12-15 (100), 12-16 (100), 12-17 (100), 12-18 (100), 12-19 (100) — by astronomy; check the weather when the night is within four days.

2044-12-15astronomy score per night — click a bar for that night2045-01-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-12-15 Thu	100	—	unknown	18:35–01:35 (good, 7.0 h)	89.7° 19:25	11.49	11%	146.8°
2044-12-16 Fri	100	—	unknown	18:35–01:30 (good, 6.92 h)	89.5° 19:20	11.5	6%	139.9°
2044-12-17 Sat	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.6° 19:20	11.5	2%	131.2°
2044-12-18 Sun	100	—	unknown	18:35–01:25 (good, 6.83 h)	89.8° 19:15	11.51	0%	121.6°
2044-12-19 Mon	100	—	unknown	18:35–01:20 (good, 6.75 h)	89.8° 19:10	11.51	0%	111.6°
2044-12-20 Tue	100	—	unknown	18:35–01:15 (good, 6.67 h)	89.7° 19:05	11.51	2%	101.4°
2044-12-21 Wed	100	—	unknown	18:35–01:10 (good, 6.58 h)	89.5° 19:05	11.51	6%	91.1°
2044-12-22 Thu	100	—	unknown	18:35–01:10 (good, 6.58 h)	89.7° 19:00	11.51	11%	80.8°
2044-12-23 Fri	100	—	unknown	18:40–01:05 (good, 6.42 h)	89.8° 18:55	11.5	17%	70.5°
2044-12-24 Sat	98	—	unknown	18:40–01:00 (good, 6.33 h)	89.8° 18:50	11.5	25%	60.5°
2044-12-25 Sun	91	—	unknown	18:40–00:55 (good, 6.25 h)	89.6° 18:45	11.5	34%	50.7°
2044-12-26 Mon	83	—	unknown	18:40–00:50 (good, 6.17 h)	89.6° 18:45	11.49	44%	41.7°
2044-12-27 Tue	67	—	unknown	18:40–00:20 (good, 5.67 h)	89.7° 18:40	11.49	54%	34.1°
2044-12-28 Wed	50	—	unknown	18:40–01:15 (marginal, 6.58 h)	89.8° 18:35	11.48	64%	29.6°
2044-12-29 Thu	33	—	unknown	18:40–00:55 (marginal, 6.25 h)	89.7° 18:30	11.47	74%	30.1°
2044-12-30 Fri	26	—	unknown	18:45–00:30 (marginal, 5.75 h)	89.5° 18:25	11.47	83%	35.8°
2044-12-31 Sat	27	—	unknown	18:45–00:15 (marginal, 5.5 h)	89.6° 18:25	11.46	91%	45.2°
2045-01-01 Sun	34	—	unknown	18:45–00:15 (marginal, 5.5 h)	89.8° 18:20	11.45	96%	56.6°
2045-01-02 Mon	49	—	unknown	18:45–19:10 (good, 0.42 h)	89.8° 18:15	11.43	100%	69.3°
2045-01-03 Tue	69	—	unknown	18:45–21:40 (good, 2.92 h)	89.7° 18:10	11.42	100%	82.5°
2045-01-04 Wed	83	—	unknown	18:45–23:15 (good, 4.5 h)	89.5° 18:10	11.41	96%	95.8°
2045-01-05 Thu	100	—	unknown	18:45–23:50 (good, 5.08 h)	89.7° 18:05	11.4	91%	108.9°
2045-01-06 Fri	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 18:00	11.38	83%	121.3°
2045-01-07 Sat	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.8° 17:55	11.37	73%	132.6°
2045-01-08 Sun	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.6° 17:50	11.35	63%	142.2°
2045-01-09 Mon	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.6° 17:50	11.33	52%	148.8°
2045-01-10 Tue	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.7° 17:45	11.32	42%	150.9°
2045-01-11 Wed	100	—	unknown	18:55–23:50 (good, 4.92 h)	89.8° 17:40	11.3	32%	148.1°
2045-01-12 Thu	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.7° 17:35	11.28	23%	141.7°
2045-01-13 Fri	100	—	unknown	18:55–23:40 (good, 4.75 h)	89.6° 17:30	11.26	16%	133.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-12-15&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.