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: 11-11 (100), 11-12 (100), 11-13 (100), 11-14 (100), 11-15 (100) — by astronomy; check the weather when the night is within four days.

2031-11-11astronomy score per night — click a bar for that night2031-12-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-11-11 Tue	100	—	unknown	19:40–05:35 (good, 9.92 h)	72.5° 00:45	10.83	10%	132.3°
2031-11-12 Wed	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.5° 00:40	10.86	5%	145.5°
2031-11-13 Thu	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.5° 00:40	10.89	1%	158.9°
2031-11-14 Fri	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.5° 00:35	10.92	0%	171.8°
2031-11-15 Sat	100	—	unknown	19:25–05:35 (good, 10.17 h)	72.5° 00:30	10.95	1%	170.7°
2031-11-16 Sun	100	—	unknown	19:20–05:35 (good, 10.25 h)	72.5° 00:25	10.98	6%	157.2°
2031-11-17 Mon	100	—	unknown	19:15–05:35 (good, 10.33 h)	72.5° 00:20	11.01	12%	142.9°
2031-11-18 Tue	100	—	unknown	19:15–05:30 (good, 10.25 h)	72.5° 00:20	11.04	21%	128.5°
2031-11-19 Wed	100	—	unknown	19:10–05:25 (good, 10.25 h)	72.5° 00:15	11.06	31%	114.2°
2031-11-20 Thu	100	—	unknown	19:15–05:20 (good, 10.08 h)	72.5° 00:10	11.09	42%	100.0°
2031-11-21 Fri	100	—	unknown	19:20–05:15 (good, 9.92 h)	72.5° 00:05	11.11	54%	86.0°
2031-11-22 Sat	100	—	unknown	19:45–05:15 (good, 9.5 h)	72.5° 00:05	11.14	64%	72.2°
2031-11-23 Sun	97	—	unknown	21:40–05:10 (good, 7.5 h)	72.5° 00:00	11.16	75%	58.7°
2031-11-24 Mon	88	—	unknown	01:25–05:05 (good, 3.67 h)	72.5° 23:55	11.19	83%	45.3°
2031-11-25 Tue	78	—	unknown	04:35–05:00 (good, 0.42 h)	72.5° 23:50	11.21	90%	32.2°
2031-11-26 Wed	38	—	unknown	00:10–05:10 (marginal, 5.0 h)	72.5° 23:45	11.23	96%	19.5°
2031-11-27 Thu	28	—	unknown	02:00–04:50 (marginal, 2.83 h)	72.5° 23:45	11.25	99%	7.8°
2031-11-28 Fri	26	—	unknown	18:40–21:05 (marginal, 2.42 h)	72.5° 23:40	11.27	100%	8.3°
2031-11-29 Sat	32	—	unknown	18:35–22:20 (marginal, 3.75 h)	72.5° 23:35	11.29	99%	19.7°
2031-11-30 Sun	43	—	unknown	18:35–23:55 (marginal, 5.33 h)	72.5° 23:30	11.31	96%	31.7°
2031-12-01 Mon	84	—	unknown	18:35–19:20 (good, 0.75 h)	72.5° 23:25	11.33	92%	43.6°
2031-12-02 Tue	91	—	unknown	18:35–23:05 (good, 4.5 h)	72.5° 23:25	11.34	86%	55.4°
2031-12-03 Wed	98	—	unknown	18:35–02:00 (good, 7.42 h)	72.5° 23:20	11.36	79%	67.2°
2031-12-04 Thu	100	—	unknown	18:35–03:25 (good, 8.83 h)	72.5° 23:15	11.38	70%	79.0°
2031-12-05 Fri	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.5° 23:10	11.39	62%	90.8°
2031-12-06 Sat	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 23:10	11.4	52%	102.7°
2031-12-07 Sun	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.5° 23:05	11.42	42%	114.9°
2031-12-08 Mon	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 23:00	11.43	33%	127.3°
2031-12-09 Tue	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 22:55	11.44	23%	140.1°
2031-12-10 Wed	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.5° 22:50	11.45	15%	153.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-11-11&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.