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.

2046-06-28astronomy score per night — click a bar for that night2046-07-27

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-06-28 Thu	—	unknown	—	42.9° 12:30	4.48	27%	57.2°
2046-06-29 Fri	—	unknown	—	42.9° 12:30	4.5	19%	48.0°
2046-06-30 Sat	—	unknown	—	42.9° 12:25	4.52	11%	39.9°
2046-07-01 Sun	—	unknown	—	42.9° 12:20	4.54	6%	34.1°
2046-07-02 Mon	—	unknown	—	42.9° 12:15	4.56	2%	32.1°
2046-07-03 Tue	—	unknown	—	42.9° 12:10	4.59	0%	35.1°
2046-07-04 Wed	—	unknown	—	42.9° 12:10	4.61	1%	42.2°
2046-07-05 Thu	—	unknown	—	42.9° 12:05	4.64	4%	51.9°
2046-07-06 Fri	—	unknown	—	42.9° 12:00	4.67	11%	63.1°
2046-07-07 Sat	—	unknown	—	42.9° 11:55	4.7	19%	74.9°
2046-07-08 Sun	—	unknown	—	42.9° 11:50	4.74	29%	87.0°
2046-07-09 Mon	—	unknown	—	42.9° 11:45	4.77	40%	99.1°
2046-07-10 Tue	—	unknown	—	42.9° 11:40	4.81	51%	110.9°
2046-07-11 Wed	—	unknown	—	42.9° 11:35	4.84	62%	122.2°
2046-07-12 Thu	—	unknown	—	42.9° 11:35	4.88	73%	132.4°
2046-07-13 Fri	—	unknown	—	42.9° 11:30	4.92	82%	141.0°
2046-07-14 Sat	—	unknown	—	42.9° 11:25	4.96	90%	146.5°
2046-07-15 Sun	—	unknown	—	42.9° 11:20	5.01	95%	147.8°
2046-07-16 Mon	—	unknown	—	42.9° 11:15	5.05	99%	144.5°
2046-07-17 Tue	—	unknown	—	42.9° 11:15	5.09	100%	137.8°
2046-07-18 Wed	—	unknown	—	42.9° 11:10	5.14	99%	129.4°
2046-07-19 Thu	—	unknown	—	42.9° 11:05	5.19	96%	120.0°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-06-28&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.