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.

Best nights for Triangulum Pinwheel: 11-10 (100), 11-11 (100), 11-12 (100), 11-13 (100), 11-14 (100) — by astronomy; check the weather when the night is within four days.

2031-11-10astronomy score per night — click a bar for that night2031-12-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-11-10 Mon	100	—	unknown	18:45–04:10 (good, 9.42 h)	79.1° 22:35	10.8	17%	143.3°
2031-11-11 Tue	100	—	unknown	18:45–04:05 (good, 9.33 h)	79.1° 22:35	10.83	10%	153.7°
2031-11-12 Wed	100	—	unknown	18:40–04:00 (good, 9.33 h)	79.1° 22:30	10.86	5%	161.1°
2031-11-13 Thu	100	—	unknown	18:40–04:00 (good, 9.33 h)	79.1° 22:25	10.89	1%	160.8°
2031-11-14 Fri	100	—	unknown	18:40–03:55 (good, 9.25 h)	79.1° 22:20	10.92	0%	152.5°
2031-11-15 Sat	100	—	unknown	18:40–03:50 (good, 9.17 h)	79.1° 22:20	10.95	1%	140.7°
2031-11-16 Sun	100	—	unknown	18:40–03:45 (good, 9.08 h)	79.1° 22:15	10.98	6%	127.7°
2031-11-17 Mon	100	—	unknown	18:40–03:40 (good, 9.0 h)	79.1° 22:10	11.01	12%	114.1°
2031-11-18 Tue	100	—	unknown	18:40–03:40 (good, 9.0 h)	79.1° 22:05	11.04	21%	100.4°
2031-11-19 Wed	100	—	unknown	18:35–03:35 (good, 9.0 h)	79.1° 22:00	11.06	31%	86.7°
2031-11-20 Thu	100	—	unknown	18:35–03:30 (good, 8.92 h)	79.1° 22:00	11.09	42%	73.1°
2031-11-21 Fri	100	—	unknown	18:35–03:25 (good, 8.83 h)	79.1° 21:55	11.11	54%	59.9°
2031-11-22 Sat	91	—	unknown	19:00–03:25 (good, 8.42 h)	79.1° 21:50	11.14	64%	47.1°
2031-11-23 Sun	83	—	unknown	02:25–03:20 (good, 0.92 h)	79.1° 21:45	11.16	75%	35.1°
2031-11-24 Mon	50	—	unknown	18:35–03:45 (marginal, 9.17 h)	79.1° 21:40	11.19	83%	24.7°
2031-11-25 Tue	35	—	unknown	18:35–03:20 (marginal, 8.75 h)	79.1° 21:40	11.21	90%	18.3°
2031-11-26 Wed	27	—	unknown	18:35–20:50 (marginal, 2.25 h)	79.1° 21:35	11.23	96%	19.9°
2031-11-27 Thu	27	—	unknown	18:35–20:50 (marginal, 2.25 h)	79.1° 21:30	11.25	99%	27.9°
2031-11-28 Fri	37	—	unknown	18:35–22:55 (marginal, 4.33 h)	79.1° 21:25	11.27	100%	38.3°
2031-11-29 Sat	57	—	unknown	18:35–02:30 (marginal, 7.92 h)	79.1° 21:25	11.29	99%	49.4°
2031-11-30 Sun	69	—	unknown	18:35–20:50 (good, 2.25 h)	79.1° 21:20	11.31	96%	60.7°
2031-12-01 Mon	100	—	unknown	18:35–23:40 (good, 5.08 h)	79.1° 21:15	11.33	92%	72.1°
2031-12-02 Tue	100	—	unknown	18:35–01:05 (good, 6.5 h)	79.1° 21:10	11.34	86%	83.4°
2031-12-03 Wed	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.1° 21:05	11.36	79%	94.7°
2031-12-04 Thu	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.1° 21:05	11.38	70%	105.9°
2031-12-05 Fri	100	—	unknown	18:35–02:25 (good, 7.83 h)	79.1° 21:00	11.39	62%	117.1°
2031-12-06 Sat	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.1° 20:55	11.4	52%	128.2°
2031-12-07 Sun	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.1° 20:50	11.42	42%	139.3°
2031-12-08 Mon	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.1° 20:45	11.43	33%	149.8°
2031-12-09 Tue	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.1° 20:45	11.44	23%	158.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-10&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.