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 Seven Sisters: 11-28 (100), 11-29 (100), 11-30 (100), 12-01 (100), 12-02 (100) — by astronomy; check the weather when the night is within four days.

2037-11-17astronomy score per night — click a bar for that night2037-12-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-11-17 Tue	99	—	unknown	21:55–05:30 (good, 7.58 h)	72.5° 00:20	11.02	78%	59.9°
2037-11-18 Wed	92	—	unknown	01:15–05:25 (good, 4.17 h)	72.5° 00:15	11.05	86%	48.2°
2037-11-19 Thu	84	—	unknown	04:25–05:25 (good, 1.0 h)	72.5° 00:15	11.08	92%	36.6°
2037-11-20 Fri	53	—	unknown	23:25–05:45 (marginal, 6.33 h)	72.5° 00:10	11.1	96%	25.0°
2037-11-21 Sat	33	—	unknown	01:35–05:20 (marginal, 3.75 h)	72.5° 00:05	11.13	99%	14.0°
2037-11-22 Sun	28	—	unknown	19:00–21:20 (marginal, 2.33 h)	72.5° 00:00	11.15	100%	8.1°
2037-11-23 Mon	31	—	unknown	18:45–22:25 (marginal, 3.67 h)	72.5° 23:55	11.18	99%	15.8°
2037-11-24 Tue	39	—	unknown	18:35–23:45 (marginal, 5.17 h)	72.5° 23:55	11.2	96%	27.6°
2037-11-25 Wed	80	—	unknown	18:45–19:15 (good, 0.5 h)	72.5° 23:50	11.22	91%	40.2°
2037-11-26 Thu	88	—	unknown	18:40–23:10 (good, 4.5 h)	72.5° 23:45	11.24	84%	53.2°
2037-11-27 Fri	96	—	unknown	18:35–02:25 (good, 7.83 h)	72.5° 23:40	11.26	75%	66.5°
2037-11-28 Sat	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 23:35	11.28	65%	80.0°
2037-11-29 Sun	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:35	11.3	54%	93.7°
2037-11-30 Mon	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:30	11.32	42%	107.6°
2037-12-01 Tue	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:25	11.34	31%	121.7°
2037-12-02 Wed	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:20	11.35	21%	135.8°
2037-12-03 Thu	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:20	11.37	12%	149.9°
2037-12-04 Fri	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.5° 23:15	11.38	6%	163.4°
2037-12-05 Sat	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.5° 23:10	11.4	2%	171.9°
2037-12-06 Sun	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.5° 23:05	11.41	0%	163.8°
2037-12-07 Mon	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.5° 23:00	11.42	1%	150.9°
2037-12-08 Tue	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.5° 23:00	11.44	5%	137.6°
2037-12-09 Wed	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 22:55	11.45	10%	124.6°
2037-12-10 Thu	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 22:50	11.46	17%	111.8°
2037-12-11 Fri	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.5° 22:45	11.47	25%	99.4°
2037-12-12 Sat	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.5° 22:40	11.47	34%	87.3°
2037-12-13 Sun	100	—	unknown	18:35–03:50 (good, 9.25 h)	72.5° 22:40	11.48	44%	75.4°
2037-12-14 Mon	100	—	unknown	18:35–03:45 (good, 9.17 h)	72.5° 22:35	11.49	53%	63.6°
2037-12-15 Tue	94	—	unknown	19:25–03:40 (good, 8.25 h)	72.5° 22:30	11.49	62%	52.0°
2037-12-16 Wed	87	—	unknown	23:00–03:35 (good, 4.58 h)	72.5° 22:25	11.5	71%	40.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-11-17&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.