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.

2034-05-26astronomy score per night — click a bar for that night2034-06-24

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-05-26 Fri	—	unknown	—	72.5° 12:55	5.04	69%	117.8°
2034-05-27 Sat	—	unknown	—	72.5° 12:50	4.99	77%	129.6°
2034-05-28 Sun	—	unknown	—	72.5° 12:45	4.95	85%	141.3°
2034-05-29 Mon	—	unknown	—	72.5° 12:40	4.91	91%	152.6°
2034-05-30 Tue	—	unknown	—	72.5° 12:40	4.87	95%	163.5°
2034-05-31 Wed	—	unknown	—	72.5° 12:35	4.83	98%	171.2°
2034-06-01 Thu	—	unknown	—	72.5° 12:30	4.79	100%	167.3°
2034-06-02 Fri	—	unknown	—	72.5° 12:25	4.76	99%	156.9°
2034-06-03 Sat	—	unknown	—	72.5° 12:20	4.72	97%	145.4°
2034-06-04 Sun	—	unknown	—	72.5° 12:20	4.69	93%	133.4°
2034-06-05 Mon	—	unknown	—	72.5° 12:15	4.66	87%	121.1°
2034-06-06 Tue	—	unknown	—	72.5° 12:10	4.63	79%	108.5°
2034-06-07 Wed	—	unknown	—	72.5° 12:05	4.61	70%	95.7°
2034-06-08 Thu	—	unknown	—	72.5° 12:00	4.58	60%	82.6°
2034-06-09 Fri	—	unknown	—	72.5° 11:55	4.56	49%	69.2°
2034-06-10 Sat	—	unknown	—	72.5° 11:50	4.53	38%	55.5°
2034-06-11 Sun	—	unknown	—	72.5° 11:45	4.51	27%	41.6°
2034-06-12 Mon	—	unknown	—	72.5° 11:45	4.5	17%	27.5°
2034-06-13 Tue	—	unknown	—	72.5° 11:40	4.48	9%	14.2°
2034-06-14 Wed	—	unknown	—	72.5° 11:35	4.47	4%	9.2°
2034-06-15 Thu	—	unknown	—	72.5° 11:30	4.45	1%	20.2°
2034-06-16 Fri	—	unknown	—	72.5° 11:25	4.44	0%	34.2°
2034-06-17 Sat	—	unknown	—	72.5° 11:25	4.43	3%	48.3°
2034-06-18 Sun	—	unknown	—	72.5° 11:20	4.43	9%	62.3°
2034-06-19 Mon	—	unknown	—	72.5° 11:15	4.42	16%	75.9°
2034-06-20 Tue	—	unknown	—	72.5° 11:10	4.42	24%	89.0°
2034-06-21 Wed	—	unknown	—	72.5° 11:05	4.42	34%	101.8°
2034-06-22 Thu	—	unknown	—	72.5° 11:05	4.43	43%	114.1°
2034-06-23 Fri	—	unknown	—	72.5° 11:00	4.43	53%	126.2°
2034-06-24 Sat	—	unknown	—	72.5° 10:55	4.44	63%	138.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-05-26&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.