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: 12-20 (100), 01-03 (100), 01-04 (100), 01-05 (100), 01-06 (100) — by astronomy; check the weather when the night is within four days.

2047-12-20astronomy score per night — click a bar for that night2048-01-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-12-20 Fri	100	—	unknown	18:35–01:20 (good, 6.75 h)	89.8° 19:10	11.51	20%	68.2°
2047-12-21 Sat	97	—	unknown	18:35–01:15 (good, 6.67 h)	89.8° 19:05	11.51	29%	57.0°
2047-12-22 Sun	89	—	unknown	18:35–01:10 (good, 6.58 h)	89.6° 19:00	11.51	39%	46.8°
2047-12-23 Mon	81	—	unknown	18:40–01:05 (good, 6.42 h)	89.6° 19:00	11.51	48%	38.0°
2047-12-24 Tue	62	—	unknown	20:40–23:35 (good, 2.92 h)	89.7° 18:55	11.5	58%	31.5°
2047-12-25 Wed	46	—	unknown	18:40–01:25 (marginal, 6.75 h)	89.8° 18:50	11.5	68%	28.5°
2047-12-26 Thu	32	—	unknown	18:40–01:10 (marginal, 6.5 h)	89.8° 18:45	11.5	76%	29.9°
2047-12-27 Fri	28	—	unknown	18:40–00:50 (marginal, 6.17 h)	89.6° 18:40	11.49	84%	35.1°
2047-12-28 Sat	28	—	unknown	18:40–00:35 (marginal, 5.92 h)	89.6° 18:40	11.49	90%	42.7°
2047-12-29 Sun	33	—	unknown	18:40–00:25 (marginal, 5.75 h)	89.8° 18:35	11.48	95%	51.7°
2047-12-30 Mon	42	—	unknown	18:40–00:30 (marginal, 5.83 h)	89.8° 18:30	11.47	98%	61.6°
2047-12-31 Tue	56	—	unknown	18:45–20:00 (good, 1.25 h)	89.7° 18:25	11.46	100%	72.0°
2048-01-01 Wed	73	—	unknown	18:45–21:50 (good, 3.08 h)	89.5° 18:20	11.45	100%	82.7°
2048-01-02 Thu	82	—	unknown	18:45–23:10 (good, 4.42 h)	89.7° 18:20	11.44	97%	93.7°
2048-01-03 Fri	100	—	unknown	18:45–23:55 (good, 5.17 h)	89.8° 18:15	11.43	93%	104.8°
2048-01-04 Sat	100	—	unknown	18:45–00:05 (good, 5.33 h)	89.8° 18:10	11.42	87%	115.9°
2048-01-05 Sun	100	—	unknown	18:45–00:05 (good, 5.33 h)	89.6° 18:05	11.41	79%	126.7°
2048-01-06 Mon	100	—	unknown	18:50–00:05 (good, 5.25 h)	89.5° 18:05	11.39	70%	136.9°
2048-01-07 Tue	100	—	unknown	18:50–00:05 (good, 5.25 h)	89.7° 18:00	11.38	59%	145.6°
2048-01-08 Wed	100	—	unknown	18:50–00:05 (good, 5.25 h)	89.8° 17:55	11.36	48%	150.9°
2048-01-09 Thu	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.8° 17:50	11.35	37%	150.7°
2048-01-10 Fri	100	—	unknown	18:50–23:55 (good, 5.08 h)	89.6° 17:45	11.33	26%	144.7°
2048-01-11 Sat	100	—	unknown	18:50–23:50 (good, 5.0 h)	89.6° 17:45	11.31	17%	135.1°
2048-01-12 Sun	100	—	unknown	18:55–23:50 (good, 4.92 h)	89.8° 17:40	11.29	9%	123.6°
2048-01-13 Mon	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.8° 17:35	11.27	3%	111.2°
2048-01-14 Tue	100	—	unknown	18:55–23:40 (good, 4.75 h)	89.7° 17:30	11.25	0%	98.4°
2048-01-15 Wed	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.5° 17:25	11.23	0%	85.7°
2048-01-16 Thu	100	—	unknown	18:55–23:30 (good, 4.58 h)	89.7° 17:25	11.21	3%	73.3°
2048-01-17 Fri	100	—	unknown	19:00–23:30 (good, 4.5 h)	89.8° 17:20	11.19	8%	61.5°
2048-01-18 Sat	94	—	unknown	19:00–23:25 (good, 4.42 h)	89.8° 17:15	11.16	14%	50.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-12-20&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.