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.

2029-08-03astronomy score per night — click a bar for that night2029-09-01

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-08-03 Fri	—	unknown	—	50.2° 17:00	5.97	36%	127.3°
2029-08-04 Sat	—	unknown	—	50.2° 17:00	6.03	27%	115.4°
2029-08-05 Sun	—	unknown	—	50.2° 16:55	6.09	19%	103.2°
2029-08-06 Mon	—	unknown	—	50.2° 16:50	6.14	11%	90.6°
2029-08-07 Tue	—	unknown	—	50.2° 16:45	6.2	6%	77.6°
2029-08-08 Wed	—	unknown	—	50.2° 16:40	6.26	2%	64.3°
2029-08-09 Thu	—	unknown	—	50.2° 16:40	6.31	0%	50.8°
2029-08-10 Fri	—	unknown	—	50.2° 16:35	6.37	1%	37.1°
2029-08-11 Sat	—	unknown	—	50.2° 16:30	6.43	5%	23.6°
2029-08-12 Sun	—	unknown	—	50.2° 16:25	6.49	11%	12.2°
2029-08-13 Mon	—	unknown	—	50.2° 16:25	6.54	19%	12.3°
2029-08-14 Tue	—	unknown	—	50.2° 16:20	6.6	29%	23.8°
2029-08-15 Wed	—	unknown	—	50.2° 16:15	6.66	40%	37.2°
2029-08-16 Thu	—	unknown	—	50.2° 16:10	6.72	52%	50.9°
2029-08-17 Fri	—	unknown	—	50.2° 16:05	6.77	63%	64.6°
2029-08-18 Sat	—	unknown	—	50.2° 16:05	6.83	73%	78.1°
2029-08-19 Sun	—	unknown	—	50.2° 16:00	6.89	82%	91.4°
2029-08-20 Mon	—	unknown	—	50.2° 15:55	6.95	90%	104.6°
2029-08-21 Tue	—	unknown	—	50.2° 15:50	7.0	95%	117.5°
2029-08-22 Wed	—	unknown	—	50.2° 15:45	7.06	98%	130.2°
2029-08-23 Thu	—	unknown	—	50.2° 15:45	7.12	100%	142.5°
2029-08-24 Fri	—	unknown	—	50.2° 15:40	7.17	99%	154.3°
2029-08-25 Sat	—	unknown	—	50.2° 15:35	7.23	96%	164.8°
2029-08-26 Sun	—	unknown	—	50.2° 15:30	7.29	92%	170.2°
2029-08-27 Mon	—	unknown	—	50.2° 15:30	7.35	86%	164.2°
2029-08-28 Tue	—	unknown	—	50.2° 15:25	7.4	79%	153.9°
2029-08-29 Wed	—	unknown	—	50.2° 15:20	7.46	71%	142.8°
2029-08-30 Thu	—	unknown	—	50.2° 15:15	7.51	62%	131.3°
2029-08-31 Fri	—	unknown	—	50.2° 15:10	7.57	52%	119.6°
2029-09-01 Sat	—	unknown	—	50.2° 15:10	7.63	43%	107.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-08-03&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.