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: 12-26 (100), 12-27 (100), 12-28 (100), 12-29 (100), 12-30 (100) — by astronomy; check the weather when the night is within four days.

2045-12-23astronomy score per night — click a bar for that night2046-01-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-12-23 Sat	47	—	unknown	18:40–01:05 (marginal, 6.42 h)	79.2° 19:45	11.5	100%	58.6°
2045-12-24 Sun	70	—	unknown	18:40–21:15 (good, 2.58 h)	79.2° 19:45	11.5	99%	72.5°
2045-12-25 Mon	81	—	unknown	18:40–23:25 (good, 4.75 h)	79.2° 19:40	11.5	95%	86.6°
2045-12-26 Tue	100	—	unknown	18:40–00:40 (good, 6.0 h)	79.2° 19:35	11.49	89%	100.8°
2045-12-27 Wed	100	—	unknown	18:40–00:50 (good, 6.17 h)	79.2° 19:30	11.49	80%	114.9°
2045-12-28 Thu	100	—	unknown	18:40–00:50 (good, 6.17 h)	79.2° 19:25	11.48	70%	128.7°
2045-12-29 Fri	100	—	unknown	18:40–00:50 (good, 6.17 h)	79.2° 19:25	11.48	59%	142.0°
2045-12-30 Sat	100	—	unknown	18:40–00:50 (good, 6.17 h)	79.2° 19:20	11.47	48%	154.4°
2045-12-31 Sun	100	—	unknown	18:45–00:50 (good, 6.08 h)	79.2° 19:15	11.46	37%	163.8°
2046-01-01 Mon	100	—	unknown	18:45–00:45 (good, 6.0 h)	79.2° 19:10	11.45	27%	164.6°
2046-01-02 Tue	100	—	unknown	18:45–00:40 (good, 5.92 h)	79.2° 19:05	11.44	18%	156.3°
2046-01-03 Wed	100	—	unknown	18:45–00:35 (good, 5.83 h)	79.2° 19:05	11.43	11%	145.1°
2046-01-04 Thu	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.2° 19:00	11.41	5%	133.2°
2046-01-05 Fri	100	—	unknown	18:45–00:30 (good, 5.75 h)	79.2° 18:55	11.4	2%	121.1°
2046-01-06 Sat	100	—	unknown	18:50–00:25 (good, 5.58 h)	79.2° 18:50	11.39	0%	109.1°
2046-01-07 Sun	100	—	unknown	18:50–00:20 (good, 5.5 h)	79.2° 18:50	11.37	1%	97.1°
2046-01-08 Mon	100	—	unknown	18:50–00:15 (good, 5.42 h)	79.2° 18:45	11.36	3%	85.3°
2046-01-09 Tue	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:40	11.34	7%	73.7°
2046-01-10 Wed	100	—	unknown	18:50–00:10 (good, 5.33 h)	79.2° 18:35	11.32	12%	62.2°
2046-01-11 Thu	95	—	unknown	18:50–00:05 (good, 5.25 h)	79.2° 18:30	11.3	19%	50.9°
2046-01-12 Fri	88	—	unknown	18:55–00:00 (good, 5.08 h)	79.2° 18:30	11.28	27%	39.9°
2046-01-13 Sat	79	—	unknown	18:55–23:55 (good, 5.0 h)	79.2° 18:25	11.26	36%	29.2°
2046-01-14 Sun	65	—	unknown	18:55–23:30 (good, 4.58 h)	79.2° 18:20	11.24	45%	19.7°
2046-01-15 Mon	49	—	unknown	20:20–21:00 (good, 0.67 h)	79.2° 18:15	11.22	55%	14.3°
2046-01-16 Tue	34	—	unknown	18:55–00:00 (marginal, 5.08 h)	79.2° 18:10	11.2	65%	17.9°
2046-01-17 Wed	23	—	unknown	19:00–23:40 (marginal, 4.67 h)	79.2° 18:10	11.18	75%	27.6°
2046-01-18 Thu	21	—	unknown	19:00–23:25 (marginal, 4.42 h)	79.2° 18:05	11.15	83%	39.6°
2046-01-19 Fri	25	—	unknown	19:00–23:20 (marginal, 4.33 h)	79.2° 18:00	11.13	91%	52.6°
2046-01-20 Sat	34	—	unknown	19:00–23:25 (marginal, 4.42 h)	79.2° 17:55	11.1	96%	66.3°
2046-01-21 Sun	48	—	unknown	19:00–20:45 (good, 1.75 h)	79.2° 17:55	11.08	100%	80.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-12-23&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.