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.

2033-06-04astronomy score per night — click a bar for that night2033-07-03

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-06-04 Sat	—	unknown	—	72.6° 12:15	4.68	50%	104.3°
2033-06-05 Sun	—	unknown	—	72.6° 12:15	4.65	59%	116.1°
2033-06-06 Mon	—	unknown	—	72.6° 12:10	4.63	68%	127.8°
2033-06-07 Tue	—	unknown	—	72.6° 12:05	4.6	76%	139.5°
2033-06-08 Wed	—	unknown	—	72.6° 12:00	4.57	84%	151.2°
2033-06-09 Thu	—	unknown	—	72.6° 11:55	4.55	91%	162.7°
2033-06-10 Fri	—	unknown	—	72.6° 11:50	4.53	96%	171.9°
2033-06-11 Sat	—	unknown	—	72.6° 11:45	4.51	99%	168.0°
2033-06-12 Sun	—	unknown	—	72.6° 11:40	4.49	100%	156.5°
2033-06-13 Mon	—	unknown	—	72.6° 11:40	4.48	99%	143.7°
2033-06-14 Tue	—	unknown	—	72.6° 11:35	4.46	95%	130.5°
2033-06-15 Wed	—	unknown	—	72.6° 11:30	4.45	90%	117.0°
2033-06-16 Thu	—	unknown	—	72.6° 11:25	4.44	82%	103.3°
2033-06-17 Fri	—	unknown	—	72.6° 11:20	4.43	73%	89.4°
2033-06-18 Sat	—	unknown	—	72.6° 11:20	4.43	62%	75.5°
2033-06-19 Sun	—	unknown	—	72.6° 11:15	4.42	51%	61.5°
2033-06-20 Mon	—	unknown	—	72.6° 11:10	4.42	39%	47.5°
2033-06-21 Tue	—	unknown	—	72.6° 11:05	4.42	28%	33.5°
2033-06-22 Wed	—	unknown	—	72.6° 11:00	4.43	19%	20.0°
2033-06-23 Thu	—	unknown	—	72.6° 11:00	4.43	11%	8.7°
2033-06-24 Fri	—	unknown	—	72.6° 10:55	4.44	5%	12.1°
2033-06-25 Sat	—	unknown	—	72.6° 10:50	4.45	1%	24.4°
2033-06-26 Sun	—	unknown	—	72.6° 10:45	4.46	0%	37.5°
2033-06-27 Mon	—	unknown	—	72.6° 10:45	4.47	2%	50.6°
2033-06-28 Tue	—	unknown	—	72.6° 10:40	4.49	5%	63.4°
2033-06-29 Wed	—	unknown	—	72.6° 10:35	4.5	10%	76.0°
2033-06-30 Thu	—	unknown	—	72.6° 10:30	4.52	17%	88.3°
2033-07-01 Fri	—	unknown	—	72.6° 10:25	4.54	25%	100.3°
2033-07-02 Sat	—	unknown	—	72.6° 10:25	4.57	33%	112.2°
2033-07-03 Sun	—	unknown	—	72.6° 10:20	4.59	43%	124.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-06-04&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.