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.

2047-07-17astronomy score per night — click a bar for that night2047-08-15

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-07-17 Wed	—	unknown	—	42.9° 11:15	5.08	24%	40.9°
2047-07-18 Thu	—	unknown	—	42.9° 11:10	5.13	16%	34.4°
2047-07-19 Fri	—	unknown	—	42.9° 11:05	5.17	9%	30.9°
2047-07-20 Sat	—	unknown	—	42.9° 11:05	5.22	4%	31.6°
2047-07-21 Sun	—	unknown	—	42.9° 11:00	5.27	1%	36.6°
2047-07-22 Mon	—	unknown	—	42.9° 10:55	5.32	0%	44.6°
2047-07-23 Tue	—	unknown	—	42.9° 10:50	5.37	1%	54.4°
2047-07-24 Wed	—	unknown	—	42.9° 10:45	5.42	5%	65.4°
2047-07-25 Thu	—	unknown	—	42.9° 10:45	5.47	10%	77.0°
2047-07-26 Fri	—	unknown	—	42.9° 10:40	5.52	18%	89.0°
2047-07-27 Sat	—	unknown	—	42.9° 10:35	5.57	28%	101.0°
2047-07-28 Sun	—	unknown	—	42.9° 10:30	5.63	39%	113.0°
2047-07-29 Mon	—	unknown	—	42.9° 10:25	5.68	50%	124.5°
2047-07-30 Tue	—	unknown	—	42.9° 10:25	5.73	62%	135.1°
2047-07-31 Wed	—	unknown	—	42.9° 10:20	5.79	72%	143.7°
2047-08-01 Thu	—	unknown	—	42.9° 10:15	5.84	82%	148.8°
2047-08-02 Fri	—	unknown	—	42.9° 10:10	5.9	90%	148.5°
2047-08-03 Sat	—	unknown	—	42.9° 10:10	5.95	96%	143.2°
2047-08-04 Sun	—	unknown	—	42.9° 10:05	6.01	99%	134.6°
2047-08-05 Mon	—	unknown	—	42.9° 10:00	6.07	100%	124.6°
2047-08-06 Tue	—	unknown	—	42.9° 09:55	6.12	99%	113.9°
2047-08-07 Wed	—	unknown	—	42.9° 09:50	6.18	95%	103.0°
2047-08-08 Thu	—	unknown	—	42.9° 09:50	6.24	90%	92.2°
2047-08-09 Fri	—	unknown	—	42.9° 09:45	6.29	83%	81.6°
2047-08-10 Sat	—	unknown	—	42.9° 09:40	6.35	75%	71.3°
2047-08-11 Sun	—	unknown	—	42.9° 09:35	6.41	67%	61.4°
2047-08-12 Mon	—	unknown	—	42.9° 09:30	6.47	57%	52.0°
2047-08-13 Tue	—	unknown	—	42.9° 09:30	6.52	48%	43.4°
2047-08-14 Wed	—	unknown	—	42.9° 09:25	6.58	39%	36.3°
2047-08-15 Thu	—	unknown	—	42.9° 09:20	6.64	30%	31.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-07-17&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.