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: 11-20 (100), 11-21 (100), 12-01 (100), 12-02 (100), 12-03 (100) — by astronomy; check the weather when the night is within four days.

2031-11-20astronomy score per night — click a bar for that night2031-12-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2031-12-10 Wed	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.1° 20:40	11.45	15%	162.0°
2031-12-11 Thu	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.1° 20:35	11.46	8%	156.7°
2031-12-12 Fri	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.1° 20:30	11.47	3%	146.0°
2031-12-13 Sat	100	—	unknown	18:35–02:00 (good, 7.42 h)	79.1° 20:30	11.48	0%	133.2°
2031-12-14 Sun	100	—	unknown	18:35–01:55 (good, 7.33 h)	79.1° 20:25	11.48	0%	119.5°
2031-12-15 Mon	100	—	unknown	18:35–01:50 (good, 7.25 h)	79.1° 20:20	11.49	4%	105.4°
2031-12-16 Tue	100	—	unknown	18:35–01:50 (good, 7.25 h)	79.1° 20:15	11.5	10%	91.1°
2031-12-17 Wed	100	—	unknown	18:35–01:45 (good, 7.17 h)	79.1° 20:10	11.5	18%	77.1°
2031-12-18 Thu	100	—	unknown	18:35–01:40 (good, 7.08 h)	79.1° 20:10	11.5	27%	63.3°
2031-12-19 Fri	94	—	unknown	18:35–01:35 (good, 7.0 h)	79.1° 20:05	11.51	38%	50.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-20&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.