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: 11-09 (100), 11-10 (100), 11-11 (100), 11-12 (100), 11-22 (100) — by astronomy; check the weather when the night is within four days.

2040-11-09astronomy score per night — click a bar for that night2040-12-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-11-09 Fri	100	—	unknown	18:45–04:10 (good, 9.42 h)	79.2° 22:40	10.8	31%	99.0°
2040-11-10 Sat	100	—	unknown	18:45–04:05 (good, 9.33 h)	79.2° 22:35	10.83	42%	85.7°
2040-11-11 Sun	100	—	unknown	18:40–04:05 (good, 9.42 h)	79.2° 22:30	10.86	53%	72.6°
2040-11-12 Mon	100	—	unknown	18:40–04:00 (good, 9.33 h)	79.2° 22:25	10.89	64%	59.7°
2040-11-13 Tue	90	—	unknown	21:50–03:55 (good, 6.08 h)	79.2° 22:25	10.92	75%	47.3°
2040-11-14 Wed	81	—	unknown	03:10–03:50 (good, 0.67 h)	79.2° 22:20	10.95	84%	35.8°
2040-11-15 Thu	44	—	unknown	18:40–04:05 (marginal, 9.42 h)	79.2° 22:15	10.98	91%	26.4°
2040-11-16 Fri	31	—	unknown	23:45–03:40 (marginal, 3.92 h)	79.2° 22:10	11.0	96%	21.4°
2040-11-17 Sat	29	—	unknown	18:40–21:05 (marginal, 2.42 h)	79.2° 22:05	11.03	99%	23.6°
2040-11-18 Sun	31	—	unknown	18:35–21:35 (marginal, 3.0 h)	79.2° 22:05	11.06	100%	31.3°
2040-11-19 Mon	47	—	unknown	18:35–00:45 (marginal, 6.17 h)	79.2° 22:00	11.08	99%	41.3°
2040-11-20 Tue	62	—	unknown	18:35–19:55 (good, 1.33 h)	79.2° 21:55	11.11	95%	52.1°
2040-11-21 Wed	95	—	unknown	18:35–22:20 (good, 3.75 h)	79.2° 21:50	11.13	90%	63.2°
2040-11-22 Thu	100	—	unknown	18:35–00:55 (good, 6.33 h)	79.2° 21:50	11.16	84%	74.3°
2040-11-23 Fri	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 21:45	11.18	76%	85.4°
2040-11-24 Sat	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:40	11.2	68%	96.4°
2040-11-25 Sun	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.2° 21:35	11.23	59%	107.4°
2040-11-26 Mon	100	—	unknown	18:35–03:00 (good, 8.42 h)	79.2° 21:30	11.25	50%	118.4°
2040-11-27 Tue	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.2° 21:30	11.27	40%	129.2°
2040-11-28 Wed	100	—	unknown	18:35–02:55 (good, 8.33 h)	79.2° 21:25	11.29	31%	139.8°
2040-11-29 Thu	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:20	11.31	22%	149.5°
2040-11-30 Fri	100	—	unknown	18:35–02:50 (good, 8.25 h)	79.2° 21:15	11.32	14%	156.9°
2040-12-01 Sat	100	—	unknown	18:35–02:45 (good, 8.17 h)	79.2° 21:10	11.34	7%	158.4°
2040-12-02 Sun	100	—	unknown	18:35–02:40 (good, 8.08 h)	79.2° 21:10	11.36	2%	152.5°
2040-12-03 Mon	100	—	unknown	18:35–02:35 (good, 8.0 h)	79.2° 21:05	11.37	0%	142.1°
2040-12-04 Tue	100	—	unknown	18:35–02:35 (good, 8.0 h)	79.2° 21:00	11.39	1%	129.8°
2040-12-05 Wed	100	—	unknown	18:35–02:30 (good, 7.92 h)	79.2° 20:55	11.4	4%	116.5°
2040-12-06 Thu	100	—	unknown	18:35–02:25 (good, 7.83 h)	79.2° 20:55	11.42	10%	102.9°
2040-12-07 Fri	100	—	unknown	18:35–02:20 (good, 7.75 h)	79.2° 20:50	11.43	18%	89.3°
2040-12-08 Sat	100	—	unknown	18:35–02:15 (good, 7.67 h)	79.2° 20:45	11.44	27%	75.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-11-09&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.