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: 10-18 (100), 10-19 (100), 10-20 (100), 10-21 (100), 10-22 (100) — by astronomy; check the weather when the night is within four days.

2044-10-18astronomy score per night — click a bar for that night2044-11-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-10-18 Tue	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.2° 01:05	9.98	5%	143.7°
2044-10-19 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.2° 01:00	10.02	1%	155.1°
2044-10-20 Thu	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:55	10.06	0%	163.4°
2044-10-21 Fri	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:55	10.1	1%	163.5°
2044-10-22 Sat	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:50	10.14	4%	155.8°
2044-10-23 Sun	100	—	unknown	20:05–06:15 (good, 10.17 h)	79.2° 00:45	10.18	9%	145.4°
2044-10-24 Mon	100	—	unknown	20:00–06:15 (good, 10.25 h)	79.2° 00:40	10.22	15%	134.3°
2044-10-25 Tue	100	—	unknown	20:00–06:10 (good, 10.17 h)	79.2° 00:40	10.26	23%	123.0°
2044-10-26 Wed	100	—	unknown	20:00–06:05 (good, 10.08 h)	79.2° 00:35	10.3	31%	111.6°
2044-10-27 Thu	100	—	unknown	19:55–06:00 (good, 10.08 h)	79.2° 00:30	10.34	40%	100.2°
2044-10-28 Fri	100	—	unknown	19:55–06:00 (good, 10.08 h)	79.2° 00:25	10.38	49%	88.8°
2044-10-29 Sat	100	—	unknown	19:55–04:55 (good, 10.0 h)	79.2° 00:20	10.41	59%	77.3°
2044-10-30 Sun	100	—	unknown	18:55–04:50 (good, 9.92 h)	79.2° 23:20	10.45	68%	65.6°
2044-10-31 Mon	96	—	unknown	20:55–04:45 (good, 7.83 h)	79.2° 23:15	10.49	77%	53.8°
2044-11-01 Tue	87	—	unknown	01:30–04:45 (good, 3.25 h)	79.2° 23:10	10.52	85%	41.8°
2044-11-02 Wed	72	—	unknown	04:20–04:40 (good, 0.33 h)	79.2° 23:05	10.56	92%	30.1°
2044-11-03 Thu	36	—	unknown	00:05–04:45 (marginal, 4.67 h)	79.2° 23:00	10.6	97%	19.8°
2044-11-04 Fri	28	—	unknown	18:50–21:00 (marginal, 2.17 h)	79.2° 23:00	10.63	99%	15.3°
2044-11-05 Sat	30	—	unknown	18:45–21:30 (marginal, 2.75 h)	79.2° 22:55	10.66	100%	21.6°
2044-11-06 Sun	39	—	unknown	18:45–23:10 (marginal, 4.42 h)	79.2° 22:50	10.7	97%	33.2°
2044-11-07 Mon	58	—	unknown	18:45–03:55 (marginal, 9.17 h)	79.2° 22:45	10.73	92%	46.5°
2044-11-08 Tue	92	—	unknown	18:45–23:15 (good, 4.5 h)	79.2° 22:45	10.76	84%	60.3°
2044-11-09 Wed	100	—	unknown	18:45–02:15 (good, 7.5 h)	79.2° 22:40	10.8	75%	74.2°
2044-11-10 Thu	100	—	unknown	18:45–03:40 (good, 8.92 h)	79.2° 22:35	10.83	65%	88.1°
2044-11-11 Fri	100	—	unknown	18:40–03:50 (good, 9.17 h)	79.2° 22:30	10.86	53%	101.7°
2044-11-12 Sat	100	—	unknown	18:40–03:55 (good, 9.25 h)	79.2° 22:25	10.89	42%	115.1°
2044-11-13 Sun	100	—	unknown	18:40–03:50 (good, 9.17 h)	79.2° 22:25	10.92	32%	128.1°
2044-11-14 Mon	100	—	unknown	18:40–03:50 (good, 9.17 h)	79.2° 22:20	10.95	22%	140.6°
2044-11-15 Tue	100	—	unknown	18:40–03:50 (good, 9.17 h)	79.2° 22:15	10.98	14%	152.2°
2044-11-16 Wed	100	—	unknown	18:40–03:45 (good, 9.08 h)	79.2° 22:10	11.01	8%	161.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-10-18&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.