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: 12-21 (100), 12-22 (100), 12-23 (100), 12-24 (100), 01-05 (100) — by astronomy; check the weather when the night is within four days.

2044-12-21astronomy score per night — click a bar for that night2045-01-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-12-21 Wed	100	—	unknown	18:35–01:25 (good, 6.83 h)	79.2° 19:55	11.51	6%	95.4°
2044-12-22 Thu	100	—	unknown	18:35–01:20 (good, 6.75 h)	79.2° 19:50	11.51	11%	84.0°
2044-12-23 Fri	100	—	unknown	18:40–01:20 (good, 6.67 h)	79.2° 19:45	11.5	17%	72.6°
2044-12-24 Sat	100	—	unknown	18:40–01:15 (good, 6.58 h)	79.2° 19:40	11.5	25%	61.1°
2044-12-25 Sun	94	—	unknown	18:40–01:10 (good, 6.5 h)	79.2° 19:40	11.5	34%	49.7°
2044-12-26 Mon	86	—	unknown	18:40–01:05 (good, 6.42 h)	79.2° 19:35	11.49	44%	38.3°
2044-12-27 Tue	67	—	unknown	18:40–00:40 (good, 6.0 h)	79.2° 19:30	11.49	54%	27.2°
2044-12-28 Wed	53	—	unknown	18:40–01:25 (marginal, 6.75 h)	79.2° 19:25	11.48	64%	17.9°
2044-12-29 Thu	35	—	unknown	18:40–01:10 (marginal, 6.5 h)	79.2° 19:20	11.47	74%	15.3°
2044-12-30 Fri	23	—	unknown	18:45–00:45 (marginal, 6.0 h)	79.2° 19:20	11.47	83%	22.7°
2044-12-31 Sat	21	—	unknown	18:45–22:35 (marginal, 3.83 h)	79.2° 19:15	11.46	91%	34.7°
2045-01-01 Sun	29	—	unknown	18:45–00:15 (marginal, 5.5 h)	79.2° 19:10	11.45	96%	48.4°
2045-01-02 Mon	44	—	unknown	18:45–00:30 (marginal, 5.75 h)	79.2° 19:05	11.43	100%	62.8°
2045-01-03 Tue	66	—	unknown	18:45–21:35 (good, 2.83 h)	79.2° 19:05	11.42	100%	77.4°
2045-01-04 Wed	82	—	unknown	18:45–23:15 (good, 4.5 h)	79.2° 19:00	11.41	96%	92.2°
2045-01-05 Thu	100	—	unknown	18:45–00:05 (good, 5.33 h)	79.2° 18:55	11.4	91%	106.7°
2045-01-06 Fri	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.2° 18:50	11.38	83%	120.9°
2045-01-07 Sat	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:45	11.37	73%	134.4°
2045-01-08 Sun	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:45	11.35	63%	147.0°
2045-01-09 Mon	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:40	11.33	52%	158.0°
2045-01-10 Tue	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:35	11.32	42%	164.8°
2045-01-11 Wed	100	—	unknown	18:55–00:05 (good, 5.17 h)	79.2° 18:30	11.3	32%	162.6°
2045-01-12 Thu	100	—	unknown	18:55–00:00 (good, 5.08 h)	79.2° 18:25	11.28	23%	154.0°
2045-01-13 Fri	100	—	unknown	18:55–23:55 (good, 5.0 h)	79.2° 18:25	11.26	16%	143.4°
2045-01-14 Sat	100	—	unknown	18:55–23:50 (good, 4.92 h)	79.2° 18:20	11.24	9%	132.3°
2045-01-15 Sun	100	—	unknown	18:55–23:50 (good, 4.92 h)	79.2° 18:15	11.22	5%	121.0°
2045-01-16 Mon	100	—	unknown	19:00–23:45 (good, 4.75 h)	79.2° 18:10	11.19	2%	109.7°
2045-01-17 Tue	100	—	unknown	19:00–23:40 (good, 4.67 h)	79.2° 18:05	11.17	0%	98.3°
2045-01-18 Wed	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:05	11.15	0%	86.8°
2045-01-19 Thu	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 18:00	11.12	3%	75.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-12-21&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.