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.

2030-05-31astronomy score per night — click a bar for that night2030-06-29

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-05-31 Fri	—	unknown	—	72.5° 12:35	4.83	0%	7.8°
2030-06-01 Sat	—	unknown	—	72.5° 12:30	4.79	0%	19.4°
2030-06-02 Sun	—	unknown	—	72.5° 12:25	4.76	2%	31.2°
2030-06-03 Mon	—	unknown	—	72.5° 12:20	4.73	6%	43.2°
2030-06-04 Tue	—	unknown	—	72.5° 12:20	4.69	12%	55.3°
2030-06-05 Wed	—	unknown	—	72.5° 12:15	4.66	19%	67.6°
2030-06-06 Thu	—	unknown	—	72.5° 12:10	4.63	28%	80.1°
2030-06-07 Fri	—	unknown	—	72.5° 12:05	4.61	37%	92.9°
2030-06-08 Sat	—	unknown	—	72.5° 12:00	4.58	48%	106.0°
2030-06-09 Sun	—	unknown	—	72.5° 11:55	4.56	58%	119.4°
2030-06-10 Mon	—	unknown	—	72.5° 11:50	4.53	69%	133.3°
2030-06-11 Tue	—	unknown	—	72.5° 11:45	4.51	79%	147.6°
2030-06-12 Wed	—	unknown	—	72.5° 11:40	4.5	88%	162.1°
2030-06-13 Thu	—	unknown	—	72.5° 11:40	4.48	95%	176.3°
2030-06-14 Fri	—	unknown	—	72.5° 11:35	4.46	99%	167.3°
2030-06-15 Sat	—	unknown	—	72.5° 11:30	4.45	100%	152.3°
2030-06-16 Sun	—	unknown	—	72.5° 11:25	4.44	98%	137.3°
2030-06-17 Mon	—	unknown	—	72.5° 11:25	4.43	93%	122.6°
2030-06-18 Tue	—	unknown	—	72.5° 11:20	4.43	86%	108.3°
2030-06-19 Wed	—	unknown	—	72.5° 11:15	4.42	78%	94.5°
2030-06-20 Thu	—	unknown	—	72.5° 11:10	4.42	68%	81.1°
2030-06-21 Fri	—	unknown	—	72.5° 11:05	4.42	58%	68.2°
2030-06-22 Sat	—	unknown	—	72.5° 11:05	4.42	48%	55.6°
2030-06-23 Sun	—	unknown	—	72.5° 11:00	4.43	38%	43.4°
2030-06-24 Mon	—	unknown	—	72.5° 10:55	4.44	29%	31.3°
2030-06-25 Tue	—	unknown	—	72.5° 10:50	4.44	21%	19.5°
2030-06-26 Wed	—	unknown	—	72.5° 10:45	4.46	14%	7.9°
2030-06-27 Thu	—	unknown	—	72.5° 10:45	4.47	8%	5.1°
2030-06-28 Fri	—	unknown	—	72.5° 10:40	4.48	4%	16.4°
2030-06-29 Sat	—	unknown	—	72.5° 10:35	4.5	1%	28.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-05-31&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.