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.

2033-05-25astronomy score per night — click a bar for that night2033-06-23

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-05-25 Wed	—	unknown	—	42.9° 14:45	5.07	9%	57.1°
2033-05-26 Thu	—	unknown	—	42.9° 14:40	5.02	3%	44.7°
2033-05-27 Fri	—	unknown	—	42.9° 14:35	4.98	0%	33.8°
2033-05-28 Sat	—	unknown	—	42.9° 14:35	4.94	0%	26.1°
2033-05-29 Sun	—	unknown	—	42.9° 14:30	4.9	3%	24.3°
2033-05-30 Mon	—	unknown	—	42.9° 14:25	4.86	8%	29.3°
2033-05-31 Tue	—	unknown	—	42.9° 14:20	4.82	14%	38.0°
2033-06-01 Wed	—	unknown	—	42.9° 14:15	4.79	22%	48.2°
2033-06-02 Thu	—	unknown	—	42.9° 14:15	4.75	31%	58.9°
2033-06-03 Fri	—	unknown	—	42.9° 14:10	4.72	40%	69.8°
2033-06-04 Sat	—	unknown	—	42.9° 14:05	4.68	50%	80.7°
2033-06-05 Sun	—	unknown	—	42.9° 14:00	4.65	59%	91.5°
2033-06-06 Mon	—	unknown	—	42.9° 13:55	4.63	68%	102.3°
2033-06-07 Tue	—	unknown	—	42.9° 13:55	4.6	76%	113.1°
2033-06-08 Wed	—	unknown	—	42.9° 13:50	4.57	84%	123.7°
2033-06-09 Thu	—	unknown	—	42.9° 13:45	4.55	91%	134.1°
2033-06-10 Fri	—	unknown	—	42.9° 13:40	4.53	96%	143.8°
2033-06-11 Sat	—	unknown	—	42.9° 13:40	4.51	99%	151.7°
2033-06-12 Sun	—	unknown	—	42.9° 13:35	4.49	100%	155.8°
2033-06-13 Mon	—	unknown	—	42.9° 13:30	4.48	99%	153.6°
2033-06-14 Tue	—	unknown	—	42.9° 13:25	4.46	95%	146.2°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-05-25&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.