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), 12-25 (100) — by astronomy; check the weather when the night is within four days.

2043-12-21astronomy score per night — click a bar for that night2044-01-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-12-21 Mon	100	—	unknown	18:35–01:25 (good, 6.83 h)	79.2° 19:55	11.51	63%	128.4°
2043-12-22 Tue	100	—	unknown	18:35–01:20 (good, 6.75 h)	79.2° 19:55	11.51	53%	140.3°
2043-12-23 Wed	100	—	unknown	18:40–01:20 (good, 6.67 h)	79.2° 19:50	11.51	43%	151.2°
2043-12-24 Thu	100	—	unknown	18:40–01:15 (good, 6.58 h)	79.2° 19:45	11.5	33%	160.0°
2043-12-25 Fri	100	—	unknown	18:40–01:15 (good, 6.58 h)	79.2° 19:40	11.5	25%	163.8°
2043-12-26 Sat	100	—	unknown	18:40–01:10 (good, 6.5 h)	79.2° 19:35	11.5	17%	160.0°
2043-12-27 Sun	100	—	unknown	18:40–01:05 (good, 6.42 h)	79.2° 19:35	11.49	11%	151.5°
2043-12-28 Mon	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.2° 19:30	11.49	6%	141.3°
2043-12-29 Tue	100	—	unknown	18:40–01:00 (good, 6.33 h)	79.2° 19:25	11.48	2%	130.5°
2043-12-30 Wed	100	—	unknown	18:40–00:55 (good, 6.25 h)	79.2° 19:20	11.47	0%	119.3°
2043-12-31 Thu	100	—	unknown	18:45–00:50 (good, 6.08 h)	79.2° 19:15	11.46	0%	107.9°
2044-01-01 Fri	100	—	unknown	18:45–00:45 (good, 6.0 h)	79.2° 19:15	11.45	2%	96.3°
2044-01-02 Sat	100	—	unknown	18:45–00:40 (good, 5.92 h)	79.2° 19:10	11.44	6%	84.5°
2044-01-03 Sun	100	—	unknown	18:45–00:40 (good, 5.92 h)	79.2° 19:05	11.43	11%	72.6°
2044-01-04 Mon	100	—	unknown	18:45–00:35 (good, 5.83 h)	79.2° 19:00	11.42	18%	60.6°
2044-01-05 Tue	93	—	unknown	18:45–00:30 (good, 5.75 h)	79.2° 19:00	11.41	27%	48.6°
2044-01-06 Wed	85	—	unknown	18:45–00:25 (good, 5.67 h)	79.2° 18:55	11.39	37%	36.7°
2044-01-07 Thu	70	—	unknown	18:50–00:00 (good, 5.17 h)	79.2° 18:50	11.38	47%	25.5°
2044-01-08 Fri	52	—	unknown	18:50–00:45 (marginal, 5.92 h)	79.2° 18:45	11.36	58%	17.2°
2044-01-09 Sat	35	—	unknown	18:50–00:30 (marginal, 5.67 h)	79.2° 18:40	11.35	69%	17.7°
2044-01-10 Sun	22	—	unknown	18:50–00:05 (marginal, 5.25 h)	79.2° 18:40	11.33	80%	27.2°
2044-01-11 Mon	22	—	unknown	18:50–23:45 (marginal, 4.92 h)	79.2° 18:35	11.31	88%	39.9°
2044-01-12 Tue	28	—	unknown	18:55–23:45 (marginal, 4.83 h)	79.2° 18:30	11.29	95%	53.7°
2044-01-13 Wed	41	—	unknown	18:55–23:55 (marginal, 5.0 h)	79.2° 18:25	11.27	99%	67.9°
2044-01-14 Thu	60	—	unknown	18:55–21:25 (good, 2.5 h)	79.2° 18:20	11.25	100%	82.3°
2044-01-15 Fri	80	—	unknown	18:55–22:55 (good, 4.0 h)	79.2° 18:20	11.23	98%	96.4°
2044-01-16 Sat	100	—	unknown	18:55–23:30 (good, 4.58 h)	79.2° 18:15	11.21	94%	110.3°
2044-01-17 Sun	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:10	11.19	87%	123.5°
2044-01-18 Mon	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 18:05	11.17	79%	136.2°
2044-01-19 Tue	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 18:05	11.14	70%	147.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-12-21&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.