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.

2033-06-15astronomy score per night — click a bar for that night2033-07-14

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-06-15 Wed	—	unknown	—	42.9° 13:20	4.45	90%	135.9°
2033-06-16 Thu	—	unknown	—	42.9° 13:20	4.44	82%	124.2°
2033-06-17 Fri	—	unknown	—	42.9° 13:15	4.43	73%	111.8°
2033-06-18 Sat	—	unknown	—	42.9° 13:10	4.43	62%	99.1°
2033-06-19 Sun	—	unknown	—	42.9° 13:05	4.42	51%	86.2°
2033-06-20 Mon	—	unknown	—	42.9° 13:00	4.42	39%	73.3°
2033-06-21 Tue	—	unknown	—	42.9° 13:00	4.42	28%	60.6°
2033-06-22 Wed	—	unknown	—	42.9° 12:55	4.43	19%	48.3°
2033-06-23 Thu	—	unknown	—	42.9° 12:50	4.43	11%	37.1°
2033-06-24 Fri	—	unknown	—	42.9° 12:45	4.44	5%	28.2°
2033-06-25 Sat	—	unknown	—	42.9° 12:45	4.45	1%	24.1°
2033-06-26 Sun	—	unknown	—	42.9° 12:40	4.46	0%	26.9°
2033-06-27 Mon	—	unknown	—	42.9° 12:35	4.47	2%	34.6°
2033-06-28 Tue	—	unknown	—	42.9° 12:30	4.49	5%	44.5°
2033-06-29 Wed	—	unknown	—	42.9° 12:25	4.5	10%	55.2°
2033-06-30 Thu	—	unknown	—	42.9° 12:25	4.52	17%	66.1°
2033-07-01 Fri	—	unknown	—	42.9° 12:20	4.54	25%	77.1°
2033-07-02 Sat	—	unknown	—	42.9° 12:15	4.57	33%	88.1°
2033-07-03 Sun	—	unknown	—	42.9° 12:10	4.59	43%	98.9°
2033-07-04 Mon	—	unknown	—	42.9° 12:05	4.62	52%	109.7°
2033-07-05 Tue	—	unknown	—	42.9° 12:00	4.65	62%	120.3°
2033-07-06 Wed	—	unknown	—	42.9° 11:55	4.68	71%	130.7°
2033-07-07 Thu	—	unknown	—	42.9° 11:50	4.71	79%	140.6°
2033-07-08 Fri	—	unknown	—	42.9° 11:50	4.74	87%	149.3°
2033-07-09 Sat	—	unknown	—	42.9° 11:45	4.78	93%	155.1°
2033-07-10 Sun	—	unknown	—	42.9° 11:40	4.81	97%	155.1°
2033-07-11 Mon	—	unknown	—	42.9° 11:35	4.85	100%	149.1°
2033-07-12 Tue	—	unknown	—	42.9° 11:30	4.89	99%	139.3°
2033-07-13 Wed	—	unknown	—	42.9° 11:30	4.93	97%	127.7°
2033-07-14 Thu	—	unknown	—	42.9° 11:25	4.97	92%	115.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-06-15&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.