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.

2047-05-24astronomy score per night — click a bar for that night2047-06-22

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-05-24 Fri	—	unknown	—	72.6° 13:05	5.13	0%	4.8°
2047-05-25 Sat	—	unknown	—	72.6° 13:00	5.09	1%	16.9°
2047-05-26 Sun	—	unknown	—	72.6° 12:55	5.04	4%	29.2°
2047-05-27 Mon	—	unknown	—	72.6° 12:50	5.0	9%	41.6°
2047-05-28 Tue	—	unknown	—	72.6° 12:45	4.96	16%	54.3°
2047-05-29 Wed	—	unknown	—	72.6° 12:45	4.91	24%	67.2°
2047-05-30 Thu	—	unknown	—	72.6° 12:40	4.87	33%	80.3°
2047-05-31 Fri	—	unknown	—	72.6° 12:35	4.84	44%	93.7°
2047-06-01 Sat	—	unknown	—	72.6° 12:30	4.8	55%	107.4°
2047-06-02 Sun	—	unknown	—	72.6° 12:25	4.76	66%	121.5°
2047-06-03 Mon	—	unknown	—	72.6° 12:25	4.73	77%	135.9°
2047-06-04 Tue	—	unknown	—	72.6° 12:20	4.7	86%	150.6°
2047-06-05 Wed	—	unknown	—	72.6° 12:15	4.67	93%	165.4°
2047-06-06 Thu	—	unknown	—	72.6° 12:10	4.64	98%	179.5°
2047-06-07 Fri	—	unknown	—	72.6° 12:05	4.61	100%	164.8°
2047-06-08 Sat	—	unknown	—	72.6° 12:00	4.58	99%	150.1°
2047-06-09 Sun	—	unknown	—	72.6° 12:00	4.56	95%	135.7°
2047-06-10 Mon	—	unknown	—	72.6° 11:50	4.54	90%	121.8°
2047-06-11 Tue	—	unknown	—	72.6° 11:50	4.52	82%	108.3°
2047-06-12 Wed	—	unknown	—	72.6° 11:45	4.5	73%	95.2°
2047-06-13 Thu	—	unknown	—	72.6° 11:40	4.48	64%	82.5°
2047-06-14 Fri	—	unknown	—	72.6° 11:35	4.47	54%	70.1°
2047-06-15 Sat	—	unknown	—	72.6° 11:30	4.45	44%	58.0°
2047-06-16 Sun	—	unknown	—	72.6° 11:30	4.44	35%	46.1°
2047-06-17 Mon	—	unknown	—	72.6° 11:25	4.44	26%	34.3°
2047-06-18 Tue	—	unknown	—	72.6° 11:20	4.43	18%	22.4°
2047-06-19 Wed	—	unknown	—	72.6° 11:15	4.42	12%	10.6°
2047-06-20 Thu	—	unknown	—	72.6° 11:10	4.42	6%	1.5°
2047-06-21 Fri	—	unknown	—	72.6° 11:10	4.42	2%	13.6°
2047-06-22 Sat	—	unknown	—	72.6° 11:05	4.42	0%	25.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-05-24&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.