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.

2043-06-25astronomy score per night — click a bar for that night2043-07-24

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-06-25 Thu	—	unknown	—	42.9° 12:45	4.44	89%	122.2°
2043-06-26 Fri	—	unknown	—	42.9° 12:40	4.45	82%	112.1°
2043-06-27 Sat	—	unknown	—	42.9° 12:35	4.47	73%	101.4°
2043-06-28 Sun	—	unknown	—	42.9° 12:35	4.48	63%	90.3°
2043-06-29 Mon	—	unknown	—	42.9° 12:30	4.5	52%	79.0°
2043-06-30 Tue	—	unknown	—	42.9° 12:25	4.51	41%	67.6°
2043-07-01 Wed	—	unknown	—	42.9° 12:20	4.53	30%	56.5°
2043-07-02 Thu	—	unknown	—	42.9° 12:15	4.56	20%	46.4°
2043-07-03 Fri	—	unknown	—	42.9° 12:15	4.58	11%	38.2°
2043-07-04 Sat	—	unknown	—	42.9° 12:10	4.61	5%	33.9°
2043-07-05 Sun	—	unknown	—	42.9° 12:05	4.63	1%	34.9°
2043-07-06 Mon	—	unknown	—	42.9° 12:00	4.66	0%	40.9°
2043-07-07 Tue	—	unknown	—	42.9° 11:55	4.69	2%	49.8°
2043-07-08 Wed	—	unknown	—	42.9° 11:50	4.73	6%	60.1°
2043-07-09 Thu	—	unknown	—	42.9° 11:45	4.76	13%	70.9°
2043-07-10 Fri	—	unknown	—	42.9° 11:40	4.8	21%	81.7°
2043-07-11 Sat	—	unknown	—	42.9° 11:40	4.83	30%	92.4°
2043-07-12 Sun	—	unknown	—	42.9° 11:35	4.87	39%	102.7°
2043-07-13 Mon	—	unknown	—	42.9° 11:30	4.91	49%	112.6°
2043-07-14 Tue	—	unknown	—	42.9° 11:25	4.95	58%	121.9°
2043-07-15 Wed	—	unknown	—	42.9° 11:20	4.99	67%	130.5°
2043-07-16 Thu	—	unknown	—	42.9° 11:20	5.04	76%	138.0°
2043-07-17 Fri	—	unknown	—	42.9° 11:15	5.08	84%	143.5°
2043-07-18 Sat	—	unknown	—	42.9° 11:10	5.13	90%	146.2°
2043-07-19 Sun	—	unknown	—	42.9° 11:05	5.17	95%	145.3°
2043-07-20 Mon	—	unknown	—	42.9° 11:05	5.22	98%	140.8°
2043-07-21 Tue	—	unknown	—	42.9° 11:00	5.27	100%	133.6°
2043-07-22 Wed	—	unknown	—	42.9° 10:55	5.32	99%	124.7°
2043-07-23 Thu	—	unknown	—	42.9° 10:50	5.37	96%	114.7°
2043-07-24 Fri	—	unknown	—	42.9° 10:45	5.42	92%	104.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-06-25&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.