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.

2046-07-20astronomy score per night — click a bar for that night2046-08-18

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-07-20 Fri	—	unknown	—	42.9° 11:00	5.23	92%	110.1°
2046-07-21 Sat	—	unknown	—	42.9° 11:00	5.28	86%	100.1°
2046-07-22 Sun	—	unknown	—	42.9° 10:55	5.33	79%	90.1°
2046-07-23 Mon	—	unknown	—	42.9° 10:50	5.38	70%	80.0°
2046-07-24 Tue	—	unknown	—	42.9° 10:45	5.43	62%	70.2°
2046-07-25 Wed	—	unknown	—	42.9° 10:40	5.48	52%	60.5°
2046-07-26 Thu	—	unknown	—	42.9° 10:40	5.53	42%	51.2°
2046-07-27 Fri	—	unknown	—	42.9° 10:35	5.59	33%	42.8°
2046-07-28 Sat	—	unknown	—	42.9° 10:30	5.64	23%	36.0°
2046-07-29 Sun	—	unknown	—	42.9° 10:25	5.69	15%	32.3°
2046-07-30 Mon	—	unknown	—	42.9° 10:20	5.75	8%	33.3°
2046-07-31 Tue	—	unknown	—	42.9° 10:20	5.8	3%	39.0°
2046-08-01 Wed	—	unknown	—	42.9° 10:15	5.86	0%	47.9°
2046-08-02 Thu	—	unknown	—	42.9° 10:10	5.91	0%	58.8°
2046-08-03 Fri	—	unknown	—	42.9° 10:05	5.97	3%	70.8°
2046-08-04 Sat	—	unknown	—	42.9° 10:05	6.02	9%	83.2°
2046-08-05 Sun	—	unknown	—	42.9° 10:00	6.08	17%	95.7°
2046-08-06 Mon	—	unknown	—	42.9° 09:55	6.14	27%	107.9°
2046-08-07 Tue	—	unknown	—	42.9° 09:50	6.19	37%	119.6°
2046-08-08 Wed	—	unknown	—	42.9° 09:45	6.25	49%	130.2°
2046-08-09 Thu	—	unknown	—	42.9° 09:45	6.31	60%	139.2°
2046-08-10 Fri	—	unknown	—	42.9° 09:40	6.36	70%	145.6°
2046-08-11 Sat	—	unknown	—	42.9° 09:35	6.42	79%	147.9°
2046-08-12 Sun	—	unknown	—	42.9° 09:30	6.48	87%	145.7°
2046-08-13 Mon	—	unknown	—	42.9° 09:25	6.54	93%	139.9°
2046-08-14 Tue	—	unknown	—	42.9° 09:25	6.59	97%	131.9°
2046-08-15 Wed	—	unknown	—	42.9° 09:20	6.65	100%	122.7°
2046-08-16 Thu	—	unknown	—	42.9° 09:15	6.71	100%	113.0°
2046-08-17 Fri	—	unknown	—	42.9° 09:10	6.77	98%	103.1°
2046-08-18 Sat	—	unknown	—	42.9° 09:10	6.82	95%	93.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-07-20&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.