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: 12-01 (100), 12-02 (100), 12-03 (100), 12-04 (100), 12-05 (100) — by astronomy; check the weather when the night is within four days.

2043-12-01astronomy score per night — click a bar for that night2043-12-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-12-01 Tue	100	—	unknown	18:35–02:35 (good, 8.0 h)	89.8° 20:25	11.33	0%	129.3°
2043-12-02 Wed	100	—	unknown	18:35–02:30 (good, 7.92 h)	89.8° 20:20	11.35	2%	120.1°
2043-12-03 Thu	100	—	unknown	18:35–02:25 (good, 7.83 h)	89.7° 20:15	11.36	5%	110.3°
2043-12-04 Fri	100	—	unknown	18:35–02:20 (good, 7.75 h)	89.5° 20:10	11.38	10%	100.1°
2043-12-05 Sat	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.7° 20:10	11.39	16%	89.8°
2043-12-06 Sun	100	—	unknown	18:35–02:15 (good, 7.67 h)	89.8° 20:05	11.41	24%	79.3°
2043-12-07 Mon	100	—	unknown	18:35–02:10 (good, 7.58 h)	89.8° 20:00	11.42	33%	68.8°
2043-12-08 Tue	96	—	unknown	18:35–02:05 (good, 7.5 h)	89.6° 19:55	11.43	42%	58.3°
2043-12-09 Wed	87	—	unknown	18:35–02:00 (good, 7.42 h)	89.5° 19:55	11.44	53%	48.3°
2043-12-10 Thu	76	—	unknown	20:35–02:00 (good, 5.42 h)	89.7° 19:50	11.45	64%	39.2°
2043-12-11 Fri	51	—	unknown	18:35–02:20 (marginal, 7.75 h)	89.8° 19:45	11.46	74%	32.6°
2043-12-12 Sat	32	—	unknown	18:35–02:00 (marginal, 7.42 h)	89.7° 19:40	11.47	83%	30.6°
2043-12-13 Sun	27	—	unknown	18:35–01:30 (marginal, 6.92 h)	89.6° 19:35	11.48	91%	34.6°
2043-12-14 Mon	31	—	unknown	18:35–00:20 (marginal, 5.75 h)	89.6° 19:35	11.49	97%	43.3°
2043-12-15 Tue	43	—	unknown	18:35–01:15 (marginal, 6.67 h)	89.8° 19:30	11.49	100%	54.5°
2043-12-16 Wed	64	—	unknown	18:35–19:55 (good, 1.33 h)	89.8° 19:25	11.5	99%	66.8°
2043-12-17 Thu	77	—	unknown	18:35–22:40 (good, 4.08 h)	89.7° 19:20	11.5	96%	79.6°
2043-12-18 Fri	100	—	unknown	18:35–00:20 (good, 5.75 h)	89.5° 19:15	11.5	90%	92.3°
2043-12-19 Sat	100	—	unknown	18:35–01:00 (good, 6.42 h)	89.6° 19:15	11.51	82%	104.7°
2043-12-20 Sun	100	—	unknown	18:35–01:05 (good, 6.5 h)	89.8° 19:10	11.51	73%	116.3°
2043-12-21 Mon	100	—	unknown	18:35–01:05 (good, 6.5 h)	89.8° 19:05	11.51	63%	127.0°
2043-12-22 Tue	100	—	unknown	18:35–01:05 (good, 6.5 h)	89.6° 19:00	11.51	53%	136.5°
2043-12-23 Wed	100	—	unknown	18:40–01:05 (good, 6.42 h)	89.5° 19:00	11.51	43%	144.0°
2043-12-24 Thu	100	—	unknown	18:40–01:05 (good, 6.42 h)	89.7° 18:55	11.5	33%	148.6°
2043-12-25 Fri	100	—	unknown	18:40–01:00 (good, 6.33 h)	89.8° 18:50	11.5	25%	149.3°
2043-12-26 Sat	100	—	unknown	18:40–00:55 (good, 6.25 h)	89.8° 18:45	11.5	17%	145.9°
2043-12-27 Sun	100	—	unknown	18:40–00:50 (good, 6.17 h)	89.6° 18:40	11.49	11%	139.6°
2043-12-28 Mon	100	—	unknown	18:40–00:45 (good, 6.08 h)	89.6° 18:40	11.49	6%	131.5°
2043-12-29 Tue	100	—	unknown	18:40–00:45 (good, 6.08 h)	89.7° 18:35	11.48	2%	122.4°
2043-12-30 Wed	100	—	unknown	18:40–00:40 (good, 6.0 h)	89.8° 18:30	11.47	0%	112.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-12-01&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.