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.

2031-10-03astronomy score per night — click a bar for that night2031-11-01

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-10-03 Fri	—	unknown	—	50.2° 13:05	9.27	89%	136.1°
2031-10-04 Sat	—	unknown	—	50.2° 13:00	9.31	82%	123.6°
2031-10-05 Sun	—	unknown	—	50.2° 12:55	9.36	73%	111.4°
2031-10-06 Mon	—	unknown	—	50.2° 12:50	9.41	64%	99.4°
2031-10-07 Tue	—	unknown	—	50.2° 12:50	9.45	55%	87.5°
2031-10-08 Wed	—	unknown	—	50.2° 12:45	9.5	46%	75.8°
2031-10-09 Thu	—	unknown	—	50.2° 12:40	9.54	36%	64.1°
2031-10-10 Fri	—	unknown	—	50.2° 12:35	9.59	27%	52.4°
2031-10-11 Sat	—	unknown	—	50.2° 12:35	9.64	19%	40.6°
2031-10-12 Sun	—	unknown	—	50.2° 12:30	9.68	12%	28.8°
2031-10-13 Mon	—	unknown	—	50.2° 12:25	9.72	6%	17.3°
2031-10-14 Tue	—	unknown	—	50.2° 12:20	9.77	2%	8.7°
2031-10-15 Wed	—	unknown	—	50.2° 12:15	9.81	0%	13.5°
2031-10-16 Thu	—	unknown	—	50.2° 12:15	9.86	0%	25.4°
2031-10-17 Fri	—	unknown	—	50.2° 12:10	9.9	3%	38.5°
2031-10-18 Sat	—	unknown	—	50.2° 12:05	9.94	8%	52.0°
2031-10-19 Sun	—	unknown	—	50.2° 12:00	9.98	15%	65.8°
2031-10-20 Mon	—	unknown	—	50.2° 11:55	10.02	24%	79.7°
2031-10-21 Tue	—	unknown	—	50.2° 11:50	10.07	34%	93.7°
2031-10-22 Wed	—	unknown	—	50.2° 11:45	10.11	46%	107.7°
2031-10-23 Thu	—	unknown	—	50.2° 11:40	10.15	57%	121.6°
2031-10-24 Fri	—	unknown	—	50.2° 11:40	10.19	68%	135.5°
2031-10-25 Sat	—	unknown	—	50.2° 10:35	10.23	78%	149.1°
2031-10-26 Sun	—	unknown	—	50.2° 10:30	10.27	87%	162.1°
2031-10-27 Mon	—	unknown	—	50.2° 10:25	10.31	93%	171.4°
2031-10-28 Tue	—	unknown	—	50.2° 10:20	10.34	98%	165.7°
2031-10-29 Wed	—	unknown	—	50.2° 10:20	10.38	100%	153.7°
2031-10-30 Thu	—	unknown	—	50.2° 10:15	10.42	100%	141.0°
2031-10-31 Fri	—	unknown	—	50.2° 10:10	10.46	97%	128.4°
2031-11-01 Sat	—	unknown	—	50.2° 10:05	10.49	93%	115.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-10-03&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.