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.

2033-07-25astronomy score per night — click a bar for that night2033-08-23

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-07-25 Mon	—	unknown	—	50.2° 17:35	5.49	0%	68.0°
2033-07-26 Tue	—	unknown	—	50.2° 17:35	5.54	0%	55.4°
2033-07-27 Wed	—	unknown	—	50.2° 17:30	5.59	3%	43.0°
2033-07-28 Thu	—	unknown	—	50.2° 17:25	5.65	7%	30.9°
2033-07-29 Fri	—	unknown	—	50.2° 17:20	5.7	12%	19.1°
2033-07-30 Sat	—	unknown	—	50.2° 17:20	5.76	19%	8.4°
2033-07-31 Sun	—	unknown	—	50.2° 17:15	5.81	27%	7.7°
2033-08-01 Mon	—	unknown	—	50.2° 17:10	5.86	36%	18.1°
2033-08-02 Tue	—	unknown	—	50.2° 17:05	5.92	45%	29.7°
2033-08-03 Wed	—	unknown	—	50.2° 17:00	5.98	55%	41.5°
2033-08-04 Thu	—	unknown	—	50.2° 17:00	6.03	64%	53.7°
2033-08-05 Fri	—	unknown	—	50.2° 16:55	6.09	74%	66.2°
2033-08-06 Sat	—	unknown	—	50.2° 16:50	6.14	82%	79.0°
2033-08-07 Sun	—	unknown	—	50.2° 16:45	6.2	90%	92.3°
2033-08-08 Mon	—	unknown	—	50.2° 16:40	6.26	95%	105.9°
2033-08-09 Tue	—	unknown	—	50.2° 16:40	6.32	99%	120.0°
2033-08-10 Wed	—	unknown	—	50.2° 16:35	6.37	100%	134.3°
2033-08-11 Thu	—	unknown	—	50.2° 16:30	6.43	98%	148.8°
2033-08-12 Fri	—	unknown	—	50.2° 16:25	6.49	93%	163.2°
2033-08-13 Sat	—	unknown	—	50.2° 16:25	6.54	86%	174.4°
2033-08-14 Sun	—	unknown	—	50.2° 16:20	6.6	77%	165.5°
2033-08-15 Mon	—	unknown	—	50.2° 16:15	6.66	66%	151.6°
2033-08-16 Tue	—	unknown	—	50.2° 16:10	6.72	55%	137.7°
2033-08-17 Wed	—	unknown	—	50.2° 16:05	6.78	44%	123.9°
2033-08-18 Thu	—	unknown	—	50.2° 16:05	6.83	34%	110.5°
2033-08-19 Fri	—	unknown	—	50.2° 16:00	6.89	24%	97.2°
2033-08-20 Sat	—	unknown	—	50.2° 15:55	6.95	16%	84.2°
2033-08-21 Sun	—	unknown	—	50.2° 15:50	7.0	9%	71.4°
2033-08-22 Mon	—	unknown	—	50.2° 15:45	7.06	4%	58.9°
2033-08-23 Tue	—	unknown	—	50.2° 15:45	7.12	1%	46.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-07-25&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.