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), 11-22 (100), 11-23 (100), 11-24 (100) — by astronomy; check the weather when the night is within four days.

2043-11-16astronomy score per night — click a bar for that night2043-12-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-11-16 Mon	27	—	unknown	18:40–21:05 (marginal, 2.42 h)	79.2° 22:15	10.98	100%	25.7°
2043-11-17 Tue	42	—	unknown	18:40–23:45 (marginal, 5.08 h)	79.2° 22:10	11.01	98%	38.5°
2043-11-18 Wed	62	—	unknown	18:40–20:10 (good, 1.5 h)	79.2° 22:05	11.04	94%	52.4°
2043-11-19 Thu	96	—	unknown	18:35–23:45 (good, 5.17 h)	79.2° 22:00	11.07	87%	66.5°
2043-11-20 Fri	100	—	unknown	18:35–02:00 (good, 7.42 h)	79.2° 22:00	11.09	78%	80.4°
2043-11-21 Sat	100	—	unknown	18:35–03:05 (good, 8.5 h)	79.2° 21:55	11.12	68%	94.0°
2043-11-22 Sun	100	—	unknown	18:35–03:10 (good, 8.58 h)	79.2° 21:50	11.14	57%	107.1°
2043-11-23 Mon	100	—	unknown	18:35–03:15 (good, 8.67 h)	79.2° 21:45	11.16	46%	119.7°
2043-11-24 Tue	100	—	unknown	18:35–03:10 (good, 8.58 h)	79.2° 21:45	11.19	36%	131.8°
2043-11-25 Wed	100	—	unknown	18:35–03:10 (good, 8.58 h)	79.2° 21:40	11.21	27%	143.1°
2043-11-26 Thu	100	—	unknown	18:35–03:05 (good, 8.5 h)	79.2° 21:35	11.23	19%	153.5°
2043-11-27 Fri	100	—	unknown	18:35–03:05 (good, 8.5 h)	79.2° 21:30	11.25	12%	161.4°
2043-11-28 Sat	100	—	unknown	18:35–03:00 (good, 8.42 h)	79.2° 21:25	11.27	6%	163.4°
2043-11-29 Sun	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.2° 21:25	11.29	3%	158.0°
2043-11-30 Mon	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:20	11.31	1%	149.0°
2043-12-01 Tue	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:15	11.33	0%	138.6°
2043-12-02 Wed	100	—	unknown	18:35–02:45 (good, 8.17 h)	79.2° 21:10	11.35	2%	127.7°
2043-12-03 Thu	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.2° 21:05	11.36	5%	116.6°
2043-12-04 Fri	100	—	unknown	18:35–02:35 (good, 8.0 h)	79.2° 21:05	11.38	10%	105.2°
2043-12-05 Sat	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.2° 21:00	11.39	16%	93.6°
2043-12-06 Sun	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.2° 20:55	11.41	24%	81.9°
2043-12-07 Mon	100	—	unknown	18:35–02:25 (good, 7.83 h)	79.2° 20:50	11.42	33%	70.0°
2043-12-08 Tue	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.2° 20:50	11.43	42%	58.0°
2043-12-09 Wed	90	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:45	11.44	53%	45.8°
2043-12-10 Thu	81	—	unknown	21:35–02:10 (good, 4.58 h)	79.2° 20:40	11.45	64%	33.7°
2043-12-11 Fri	52	—	unknown	18:35–02:35 (marginal, 8.0 h)	79.2° 20:35	11.46	74%	22.7°
2043-12-12 Sat	34	—	unknown	18:35–02:15 (marginal, 7.67 h)	79.2° 20:30	11.47	83%	16.3°
2043-12-13 Sun	24	—	unknown	22:25–01:45 (marginal, 3.33 h)	79.2° 20:30	11.48	91%	20.8°
2043-12-14 Mon	22	—	unknown	18:35–20:25 (marginal, 1.83 h)	79.2° 20:25	11.49	97%	32.2°
2043-12-15 Tue	36	—	unknown	18:35–23:45 (marginal, 5.17 h)	79.2° 20:20	11.49	100%	45.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-11-16&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.