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.

2045-06-06astronomy score per night — click a bar for that night2045-07-05

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-06-06 Tue	—	unknown	—	42.9° 13:55	4.62	59%	104.9°
2045-06-07 Wed	—	unknown	—	42.9° 13:55	4.6	49%	94.9°
2045-06-08 Thu	—	unknown	—	42.9° 13:50	4.57	40%	84.7°
2045-06-09 Fri	—	unknown	—	42.9° 13:45	4.55	30%	74.3°
2045-06-10 Sat	—	unknown	—	42.9° 13:40	4.53	21%	63.9°
2045-06-11 Sun	—	unknown	—	42.9° 13:40	4.51	13%	53.8°
2045-06-12 Mon	—	unknown	—	42.9° 13:35	4.49	7%	44.4°
2045-06-13 Tue	—	unknown	—	42.9° 13:30	4.47	2%	36.9°
2045-06-14 Wed	—	unknown	—	42.9° 13:25	4.46	0%	33.2°
2045-06-15 Thu	—	unknown	—	42.9° 13:20	4.45	1%	34.9°
2045-06-16 Fri	—	unknown	—	42.9° 13:20	4.44	5%	41.4°
2045-06-17 Sat	—	unknown	—	42.9° 13:15	4.43	11%	51.0°
2045-06-18 Sun	—	unknown	—	42.9° 13:10	4.43	20%	62.1°
2045-06-19 Mon	—	unknown	—	42.9° 13:05	4.42	30%	73.8°
2045-06-20 Tue	—	unknown	—	42.9° 13:00	4.42	41%	85.6°
2045-06-21 Wed	—	unknown	—	42.9° 13:00	4.42	52%	97.2°
2045-06-22 Thu	—	unknown	—	42.9° 12:55	4.43	63%	108.5°
2045-06-23 Fri	—	unknown	—	42.9° 12:50	4.43	73%	119.2°
2045-06-24 Sat	—	unknown	—	42.9° 12:45	4.44	82%	129.0°
2045-06-25 Sun	—	unknown	—	42.9° 12:45	4.45	89%	137.4°
2045-06-26 Mon	—	unknown	—	42.9° 12:40	4.46	94%	143.7°
2045-06-27 Tue	—	unknown	—	42.9° 12:35	4.47	98%	146.7°
2045-06-28 Wed	—	unknown	—	42.9° 12:30	4.49	100%	145.9°
2045-06-29 Thu	—	unknown	—	42.9° 12:25	4.51	100%	141.5°
2045-06-30 Fri	—	unknown	—	42.9° 12:25	4.53	98%	134.6°
2045-07-01 Sat	—	unknown	—	42.9° 12:20	4.55	94%	126.4°
2045-07-02 Sun	—	unknown	—	42.9° 12:15	4.57	88%	117.4°
2045-07-03 Mon	—	unknown	—	42.9° 12:10	4.59	82%	107.8°
2045-07-04 Tue	—	unknown	—	42.9° 12:05	4.62	74%	98.0°
2045-07-05 Wed	—	unknown	—	42.9° 12:00	4.65	65%	88.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-06-06&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.