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.

2044-07-17astronomy score per night — click a bar for that night2044-08-15

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-07-17 Sun	—	unknown	—	42.9° 11:10	5.11	52%	65.2°
2044-07-18 Mon	—	unknown	—	42.9° 11:05	5.16	41%	54.8°
2044-07-19 Tue	—	unknown	—	42.9° 11:05	5.21	30%	45.3°
2044-07-20 Wed	—	unknown	—	42.9° 11:00	5.26	20%	37.7°
2044-07-21 Thu	—	unknown	—	42.9° 10:55	5.3	12%	33.9°
2044-07-22 Fri	—	unknown	—	42.9° 10:50	5.35	5%	35.5°
2044-07-23 Sat	—	unknown	—	42.9° 10:50	5.4	1%	42.1°
2044-07-24 Sun	—	unknown	—	42.9° 10:45	5.45	0%	51.8°
2044-07-25 Mon	—	unknown	—	42.9° 10:40	5.51	2%	63.0°
2044-07-26 Tue	—	unknown	—	42.9° 10:35	5.56	7%	74.7°
2044-07-27 Wed	—	unknown	—	42.9° 10:30	5.61	14%	86.5°
2044-07-28 Thu	—	unknown	—	42.9° 10:30	5.67	22%	97.9°
2044-07-29 Fri	—	unknown	—	42.9° 10:25	5.72	32%	108.7°
2044-07-30 Sat	—	unknown	—	42.9° 10:20	5.77	42%	118.9°
2044-07-31 Sun	—	unknown	—	42.9° 10:15	5.83	52%	128.2°
2044-08-01 Mon	—	unknown	—	42.9° 10:10	5.88	62%	136.2°
2044-08-02 Tue	—	unknown	—	42.9° 10:10	5.94	71%	142.4°
2044-08-03 Wed	—	unknown	—	42.9° 10:05	5.99	79%	145.8°
2044-08-04 Thu	—	unknown	—	42.9° 10:00	6.05	86%	145.8°
2044-08-05 Fri	—	unknown	—	42.9° 09:55	6.11	92%	142.3°
2044-08-06 Sat	—	unknown	—	42.9° 09:55	6.16	96%	136.2°
2044-08-07 Sun	—	unknown	—	42.9° 09:50	6.22	99%	128.4°
2044-08-08 Mon	—	unknown	—	42.9° 09:45	6.28	100%	119.4°
2044-08-09 Tue	—	unknown	—	42.9° 09:40	6.33	99%	109.7°
2044-08-10 Wed	—	unknown	—	42.9° 09:35	6.39	96%	99.5°
2044-08-11 Thu	—	unknown	—	42.9° 09:35	6.45	91%	89.1°
2044-08-12 Fri	—	unknown	—	42.9° 09:30	6.51	84%	78.4°
2044-08-13 Sat	—	unknown	—	42.9° 09:25	6.56	76%	67.8°
2044-08-14 Sun	—	unknown	—	42.9° 09:20	6.62	66%	57.5°
2044-08-15 Mon	—	unknown	—	42.9° 09:15	6.68	55%	47.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-07-17&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.