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: 12-12 (100), 12-13 (100), 12-14 (100), 12-15 (100), 12-16 (100) — by astronomy; check the weather when the night is within four days.

2030-12-07astronomy score per night — click a bar for that night2031-01-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-12-07 Sat	24	—	unknown	18:35–20:25 (marginal, 1.83 h)	79.1° 20:50	11.42	96%	27.2°
2030-12-08 Sun	31	—	unknown	18:35–22:00 (marginal, 3.42 h)	79.1° 20:45	11.43	99%	37.3°
2030-12-09 Mon	45	—	unknown	18:35–01:10 (marginal, 6.58 h)	79.1° 20:40	11.44	100%	48.1°
2030-12-10 Tue	65	—	unknown	18:35–19:35 (good, 1.0 h)	79.1° 20:40	11.45	99%	59.2°
2030-12-11 Wed	74	—	unknown	18:35–22:05 (good, 3.5 h)	79.1° 20:35	11.46	96%	70.4°
2030-12-12 Thu	100	—	unknown	18:35–23:55 (good, 5.33 h)	79.1° 20:30	11.47	92%	81.8°
2030-12-13 Fri	100	—	unknown	18:35–01:15 (good, 6.67 h)	79.1° 20:25	11.48	86%	93.3°
2030-12-14 Sat	100	—	unknown	18:35–01:35 (good, 7.0 h)	79.1° 20:25	11.49	79%	104.9°
2030-12-15 Sun	100	—	unknown	18:35–01:40 (good, 7.08 h)	79.1° 20:20	11.49	70%	116.6°
2030-12-16 Mon	100	—	unknown	18:35–01:40 (good, 7.08 h)	79.1° 20:15	11.5	61%	128.4°
2030-12-17 Tue	100	—	unknown	18:35–01:40 (good, 7.08 h)	79.1° 20:10	11.5	51%	140.2°
2030-12-18 Wed	100	—	unknown	18:35–01:35 (good, 7.0 h)	79.1° 20:05	11.5	40%	151.6°
2030-12-19 Thu	100	—	unknown	18:35–01:35 (good, 7.0 h)	79.1° 20:05	11.51	30%	160.9°
2030-12-20 Fri	100	—	unknown	18:35–01:30 (good, 6.92 h)	79.1° 20:00	11.51	20%	163.1°
2030-12-21 Sat	100	—	unknown	18:35–01:30 (good, 6.92 h)	79.1° 19:55	11.51	11%	155.3°
2030-12-22 Sun	100	—	unknown	18:35–01:25 (good, 6.83 h)	79.1° 19:50	11.51	5%	142.9°
2030-12-23 Mon	100	—	unknown	18:40–01:20 (good, 6.67 h)	79.1° 19:45	11.51	1%	129.1°
2030-12-24 Tue	100	—	unknown	18:40–01:15 (good, 6.58 h)	79.1° 19:45	11.5	0%	114.6°
2030-12-25 Wed	100	—	unknown	18:40–01:10 (good, 6.5 h)	79.1° 19:40	11.5	2%	100.1°
2030-12-26 Thu	100	—	unknown	18:40–01:10 (good, 6.5 h)	79.1° 19:35	11.5	7%	85.8°
2030-12-27 Fri	100	—	unknown	18:40–01:05 (good, 6.42 h)	79.1° 19:30	11.49	14%	71.8°
2030-12-28 Sat	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.1° 19:30	11.48	23%	58.4°
2030-12-29 Sun	92	—	unknown	18:40–00:55 (good, 6.25 h)	79.1° 19:25	11.48	33%	45.7°
2030-12-30 Mon	83	—	unknown	18:40–00:50 (good, 6.17 h)	79.1° 19:20	11.47	44%	34.0°
2030-12-31 Tue	66	—	unknown	18:45–00:20 (good, 5.58 h)	79.1° 19:15	11.46	54%	23.8°
2031-01-01 Wed	50	—	unknown	18:45–01:10 (marginal, 6.42 h)	79.1° 19:10	11.45	64%	17.1°
2031-01-02 Thu	35	—	unknown	18:45–00:55 (marginal, 6.17 h)	79.1° 19:10	11.44	72%	17.9°
2031-01-03 Fri	25	—	unknown	18:45–00:35 (marginal, 5.83 h)	79.1° 19:05	11.43	81%	25.0°
2031-01-04 Sat	23	—	unknown	18:45–00:15 (marginal, 5.5 h)	79.1° 19:00	11.42	88%	34.7°
2031-01-05 Sun	27	—	unknown	18:45–00:10 (marginal, 5.42 h)	79.1° 18:55	11.4	93%	45.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-12-07&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.