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.

Best nights for Seven Sisters: 07-07 (1) — by astronomy; check the weather when the night is within four days.

2028-06-08astronomy score per night — click a bar for that night2028-07-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-06-08 Thu	0	—	unknown	—	72.5° 12:00	4.57	97%	140.9°
2028-06-09 Fri	0	—	unknown	—	72.5° 11:50	4.54	92%	128.2°
2028-06-10 Sat	0	—	unknown	—	72.5° 11:50	4.52	86%	115.8°
2028-06-11 Sun	0	—	unknown	—	72.5° 11:45	4.5	79%	103.7°
2028-06-12 Mon	0	—	unknown	—	72.5° 11:40	4.49	71%	91.7°
2028-06-13 Tue	0	—	unknown	—	72.5° 11:35	4.47	62%	79.8°
2028-06-14 Wed	0	—	unknown	—	72.5° 11:35	4.46	52%	68.0°
2028-06-15 Thu	0	—	unknown	—	72.5° 11:30	4.45	43%	56.1°
2028-06-16 Fri	0	—	unknown	—	72.5° 11:25	4.44	34%	44.0°
2028-06-17 Sat	0	—	unknown	—	72.5° 11:20	4.43	25%	31.8°
2028-06-18 Sun	0	—	unknown	—	72.5° 11:15	4.43	16%	19.2°
2028-06-19 Mon	0	—	unknown	—	72.5° 11:15	4.42	10%	6.4°
2028-06-20 Tue	0	—	unknown	—	72.5° 11:10	4.42	4%	6.9°
2028-06-21 Wed	0	—	unknown	—	72.5° 11:05	4.42	1%	20.5°
2028-06-22 Thu	0	—	unknown	—	72.5° 11:00	4.43	0%	34.4°
2028-06-23 Fri	0	—	unknown	—	72.5° 10:55	4.43	2%	48.6°
2028-06-24 Sat	0	—	unknown	—	72.5° 10:55	4.44	6%	63.0°
2028-06-25 Sun	0	—	unknown	—	72.5° 10:50	4.45	13%	77.5°
2028-06-26 Mon	0	—	unknown	—	72.5° 10:45	4.46	22%	91.9°
2028-06-27 Tue	0	—	unknown	—	72.5° 10:40	4.47	32%	106.3°
2028-06-28 Wed	0	—	unknown	—	72.5° 10:35	4.49	43%	120.6°
2028-06-29 Thu	0	—	unknown	—	72.5° 10:35	4.51	55%	134.7°
2028-06-30 Fri	0	—	unknown	—	72.5° 10:30	4.53	66%	148.6°
2028-07-01 Sat	0	—	unknown	—	72.5° 10:25	4.55	76%	162.3°
2028-07-02 Sun	0	—	unknown	—	72.5° 10:20	4.57	85%	175.8°
2028-07-03 Mon	0	—	unknown	—	72.5° 10:20	4.6	92%	170.9°
2028-07-04 Tue	0	—	unknown	—	72.5° 10:15	4.62	96%	157.8°
2028-07-05 Wed	0	—	unknown	—	72.5° 10:10	4.65	99%	144.9°
2028-07-06 Thu	0	—	unknown	—	72.5° 10:05	4.68	100%	132.3°
2028-07-07 Fri	1	—	unknown	—	72.5° 10:00	4.71	99%	119.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-06-08&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.