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.

2038-06-06astronomy score per night — click a bar for that night2038-07-05

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-06-06 Sun	—	unknown	—	72.5° 12:10	4.63	15%	62.1°
2038-06-07 Mon	—	unknown	—	72.5° 12:05	4.6	23%	75.2°
2038-06-08 Tue	—	unknown	—	72.5° 12:00	4.58	33%	88.5°
2038-06-09 Wed	—	unknown	—	72.5° 11:55	4.55	44%	102.1°
2038-06-10 Thu	—	unknown	—	72.5° 11:50	4.53	55%	115.9°
2038-06-11 Fri	—	unknown	—	72.5° 11:45	4.51	66%	129.9°
2038-06-12 Sat	—	unknown	—	72.5° 11:45	4.49	77%	144.1°
2038-06-13 Sun	—	unknown	—	72.5° 11:40	4.48	86%	158.1°
2038-06-14 Mon	—	unknown	—	72.5° 11:35	4.46	93%	170.4°
2038-06-15 Tue	—	unknown	—	72.5° 11:30	4.45	98%	168.5°
2038-06-16 Wed	—	unknown	—	72.5° 11:25	4.44	100%	155.6°
2038-06-17 Thu	—	unknown	—	72.5° 11:25	4.43	99%	141.7°
2038-06-18 Fri	—	unknown	—	72.5° 11:20	4.43	96%	128.0°
2038-06-19 Sat	—	unknown	—	72.5° 11:15	4.42	90%	114.6°
2038-06-20 Sun	—	unknown	—	72.5° 11:10	4.42	83%	101.5°
2038-06-21 Mon	—	unknown	—	72.5° 11:05	4.42	74%	88.8°
2038-06-22 Tue	—	unknown	—	72.5° 11:05	4.43	65%	76.5°
2038-06-23 Wed	—	unknown	—	72.5° 11:00	4.43	56%	64.4°
2038-06-24 Thu	—	unknown	—	72.5° 10:55	4.44	46%	52.6°
2038-06-25 Fri	—	unknown	—	72.5° 10:50	4.45	37%	40.9°
2038-06-26 Sat	—	unknown	—	72.5° 10:50	4.46	28%	29.4°
2038-06-27 Sun	—	unknown	—	72.5° 10:45	4.47	20%	18.2°
2038-06-28 Mon	—	unknown	—	72.5° 10:40	4.48	13%	8.8°
2038-06-29 Tue	—	unknown	—	72.5° 10:35	4.5	7%	10.7°
2038-06-30 Wed	—	unknown	—	72.5° 10:30	4.52	3%	21.2°
2038-07-01 Thu	—	unknown	—	72.5° 10:30	4.54	0%	33.3°
2038-07-02 Fri	—	unknown	—	72.5° 10:25	4.56	0%	45.9°
2038-07-03 Sat	—	unknown	—	72.5° 10:20	4.59	2%	58.8°
2038-07-04 Sun	—	unknown	—	72.5° 10:15	4.61	6%	72.0°
2038-07-05 Mon	—	unknown	—	72.5° 10:10	4.64	13%	85.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-06-06&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.