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), 12-04 (100) — by astronomy; check the weather when the night is within four days.

2028-11-20astronomy score per night — click a bar for that night2028-12-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-11-20 Mon	100	—	unknown	18:35–03:25 (good, 8.83 h)	79.1° 21:55	11.11	21%	98.2°
2028-11-21 Tue	100	—	unknown	18:35–03:25 (good, 8.83 h)	79.1° 21:50	11.13	30%	85.9°
2028-11-22 Wed	100	—	unknown	18:35–03:20 (good, 8.75 h)	79.1° 21:45	11.16	40%	74.1°
2028-11-23 Thu	100	—	unknown	18:35–03:15 (good, 8.67 h)	79.1° 21:45	11.18	49%	62.4°
2028-11-24 Fri	94	—	unknown	18:35–03:10 (good, 8.58 h)	79.1° 21:40	11.2	59%	51.1°
2028-11-25 Sat	86	—	unknown	21:55–03:10 (good, 5.25 h)	79.1° 21:35	11.22	68%	40.0°
2028-11-26 Sun	75	—	unknown	02:40–03:05 (good, 0.42 h)	79.1° 21:30	11.25	76%	29.4°
2028-11-27 Mon	45	—	unknown	18:35–03:20 (marginal, 8.75 h)	79.1° 21:30	11.27	84%	20.0°
2028-11-28 Tue	31	—	unknown	18:35–03:00 (marginal, 8.42 h)	79.1° 21:25	11.29	90%	14.6°
2028-11-29 Wed	25	—	unknown	18:35–20:25 (marginal, 1.83 h)	79.1° 21:20	11.3	95%	17.7°
2028-11-30 Thu	24	—	unknown	18:35–20:25 (marginal, 1.83 h)	79.1° 21:15	11.32	98%	26.9°
2028-12-01 Fri	34	—	unknown	18:35–22:20 (marginal, 3.75 h)	79.1° 21:10	11.34	100%	38.1°
2028-12-02 Sat	53	—	unknown	18:35–02:10 (marginal, 7.58 h)	79.1° 21:10	11.36	99%	50.3°
2028-12-03 Sun	70	—	unknown	18:35–20:55 (good, 2.33 h)	79.1° 21:05	11.37	96%	62.9°
2028-12-04 Mon	100	—	unknown	18:35–23:50 (good, 5.25 h)	79.1° 21:00	11.39	91%	75.8°
2028-12-05 Tue	100	—	unknown	18:35–01:25 (good, 6.83 h)	79.1° 20:55	11.4	84%	89.0°
2028-12-06 Wed	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.1° 20:50	11.41	75%	102.3°
2028-12-07 Thu	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.1° 20:50	11.43	65%	115.7°
2028-12-08 Fri	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.1° 20:45	11.44	54%	129.1°
2028-12-09 Sat	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.1° 20:40	11.45	42%	142.3°
2028-12-10 Sun	100	—	unknown	18:35–02:10 (good, 7.58 h)	79.1° 20:35	11.46	31%	154.7°
2028-12-11 Mon	100	—	unknown	18:35–02:05 (good, 7.5 h)	79.1° 20:35	11.47	21%	164.1°
2028-12-12 Tue	100	—	unknown	18:35–02:00 (good, 7.42 h)	79.1° 20:30	11.48	12%	163.8°
2028-12-13 Wed	100	—	unknown	18:35–01:55 (good, 7.33 h)	79.1° 20:25	11.48	6%	154.1°
2028-12-14 Thu	100	—	unknown	18:35–01:55 (good, 7.33 h)	79.1° 20:20	11.49	2%	141.8°
2028-12-15 Fri	100	—	unknown	18:35–01:50 (good, 7.25 h)	79.1° 20:15	11.49	0%	128.9°
2028-12-16 Sat	100	—	unknown	18:35–01:45 (good, 7.17 h)	79.1° 20:15	11.5	1%	115.9°
2028-12-17 Sun	100	—	unknown	18:35–01:40 (good, 7.08 h)	79.1° 20:10	11.5	4%	103.1°
2028-12-18 Mon	100	—	unknown	18:35–01:35 (good, 7.0 h)	79.1° 20:05	11.51	9%	90.5°
2028-12-19 Tue	100	—	unknown	18:35–01:35 (good, 7.0 h)	79.1° 20:00	11.51	15%	78.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-11-20&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.