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.

2045-06-02astronomy score per night — click a bar for that night2045-07-01

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-06-02 Fri	—	unknown	—	72.6° 12:25	4.75	90%	130.8°
2045-06-03 Sat	—	unknown	—	72.6° 12:20	4.71	84%	118.8°
2045-06-04 Sun	—	unknown	—	72.6° 12:15	4.68	76%	106.9°
2045-06-05 Mon	—	unknown	—	72.6° 12:15	4.65	68%	95.1°
2045-06-06 Tue	—	unknown	—	72.6° 12:10	4.62	59%	83.2°
2045-06-07 Wed	—	unknown	—	72.6° 12:05	4.6	49%	71.2°
2045-06-08 Thu	—	unknown	—	72.6° 12:00	4.57	40%	59.0°
2045-06-09 Fri	—	unknown	—	72.6° 11:55	4.55	30%	46.5°
2045-06-10 Sat	—	unknown	—	72.6° 11:50	4.53	21%	33.7°
2045-06-11 Sun	—	unknown	—	72.6° 11:45	4.51	13%	20.5°
2045-06-12 Mon	—	unknown	—	72.6° 11:40	4.49	7%	6.8°
2045-06-13 Tue	—	unknown	—	72.6° 11:40	4.47	2%	7.4°
2045-06-14 Wed	—	unknown	—	72.6° 11:35	4.46	0%	21.7°
2045-06-15 Thu	—	unknown	—	72.6° 11:30	4.45	1%	36.4°
2045-06-16 Fri	—	unknown	—	72.6° 11:25	4.44	5%	51.2°
2045-06-17 Sat	—	unknown	—	72.6° 11:20	4.43	11%	66.1°
2045-06-18 Sun	—	unknown	—	72.6° 11:20	4.43	20%	80.8°
2045-06-19 Mon	—	unknown	—	72.6° 11:15	4.42	30%	95.3°
2045-06-20 Tue	—	unknown	—	72.6° 11:10	4.42	41%	109.5°
2045-06-21 Wed	—	unknown	—	72.6° 11:05	4.42	52%	123.4°
2045-06-22 Thu	—	unknown	—	72.6° 11:05	4.43	63%	137.0°
2045-06-23 Fri	—	unknown	—	72.6° 11:00	4.43	73%	150.3°
2045-06-24 Sat	—	unknown	—	72.6° 10:55	4.44	82%	163.4°
2045-06-25 Sun	—	unknown	—	72.6° 10:50	4.45	89%	176.2°
2045-06-26 Mon	—	unknown	—	72.6° 10:45	4.46	94%	171.0°
2045-06-27 Tue	—	unknown	—	72.6° 10:45	4.47	98%	158.6°
2045-06-28 Wed	—	unknown	—	72.6° 10:40	4.49	100%	146.3°
2045-06-29 Thu	—	unknown	—	72.6° 10:35	4.51	100%	134.2°
2045-06-30 Fri	—	unknown	—	72.6° 10:30	4.53	98%	122.2°
2045-07-01 Sat	—	unknown	—	72.6° 10:25	4.55	94%	110.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-06-02&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.