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 3C 273: 11-07 (2), 11-08 (2), 11-02 (1), 11-03 (1), 11-04 (1) — by astronomy; check the weather when the night is within four days.

2044-10-10astronomy score per night — click a bar for that night2044-11-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-10-10 Mon	0	—	unknown	—	50.1° 12:35	9.63	82%	116.5°
2044-10-11 Tue	0	—	unknown	—	50.1° 12:30	9.67	72%	102.4°
2044-10-12 Wed	0	—	unknown	—	50.1° 12:25	9.72	61%	88.3°
2044-10-13 Thu	0	—	unknown	—	50.1° 12:20	9.76	50%	74.3°
2044-10-14 Fri	0	—	unknown	—	50.1° 12:20	9.81	39%	60.3°
2044-10-15 Sat	0	—	unknown	—	50.1° 12:15	9.85	28%	46.4°
2044-10-16 Sun	0	—	unknown	—	50.1° 12:10	9.89	18%	32.7°
2044-10-17 Mon	0	—	unknown	—	50.1° 12:05	9.93	11%	19.5°
2044-10-18 Tue	0	—	unknown	—	50.1° 12:00	9.98	5%	8.3°
2044-10-19 Wed	0	—	unknown	—	50.1° 11:55	10.02	1%	11.3°
2044-10-20 Thu	0	—	unknown	—	50.1° 11:50	10.06	0%	23.1°
2044-10-21 Fri	0	—	unknown	—	50.1° 11:45	10.1	1%	35.7°
2044-10-22 Sat	0	—	unknown	—	50.1° 11:45	10.14	4%	48.2°
2044-10-23 Sun	0	—	unknown	—	50.1° 11:40	10.18	9%	60.5°
2044-10-24 Mon	0	—	unknown	—	50.1° 11:35	10.22	15%	72.6°
2044-10-25 Tue	0	—	unknown	—	50.1° 11:30	10.26	23%	84.5°
2044-10-26 Wed	0	—	unknown	—	50.1° 11:25	10.3	31%	96.3°
2044-10-27 Thu	0	—	unknown	—	50.1° 11:25	10.34	40%	108.0°
2044-10-28 Fri	0	—	unknown	—	50.1° 11:20	10.38	49%	119.7°
2044-10-29 Sat	0	—	unknown	—	50.1° 10:15	10.41	59%	131.6°
2044-10-30 Sun	0	—	unknown	—	50.1° 10:10	10.45	68%	143.5°
2044-10-31 Mon	0	—	unknown	—	50.1° 10:05	10.49	77%	155.6°
2044-11-01 Tue	0	—	unknown	—	50.1° 10:05	10.52	85%	167.2°
2044-11-02 Wed	1	—	unknown	—	50.1° 10:00	10.56	92%	172.6°
2044-11-03 Thu	1	—	unknown	—	50.1° 09:55	10.6	97%	162.6°
2044-11-04 Fri	1	—	unknown	—	50.1° 09:50	10.63	99%	149.4°
2044-11-05 Sat	1	—	unknown	—	50.1° 09:50	10.66	100%	135.4°
2044-11-06 Sun	1	—	unknown	—	50.1° 09:45	10.7	97%	121.1°
2044-11-07 Mon	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.1° 09:40	10.73	92%	106.7°
2044-11-08 Tue	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.1° 09:35	10.76	84%	92.2°

Download: CSV · JSON

💡 API

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