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: 11-10 (100), 11-11 (100), 11-12 (100), 11-13 (100), 11-14 (100) — by astronomy; check the weather when the night is within four days.

2045-11-10astronomy score per night — click a bar for that night2045-12-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-11-10 Fri	100	—	unknown	19:40–05:30 (good, 9.83 h)	72.6° 00:50	10.82	5%	165.7°
2045-11-11 Sat	100	—	unknown	19:40–05:35 (good, 9.92 h)	72.6° 00:45	10.85	10%	152.7°
2045-11-12 Sun	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.6° 00:40	10.88	17%	140.0°
2045-11-13 Mon	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.6° 00:35	10.91	25%	127.7°
2045-11-14 Tue	100	—	unknown	19:30–05:35 (good, 10.08 h)	72.6° 00:30	10.94	34%	115.5°
2045-11-15 Wed	100	—	unknown	19:30–05:40 (good, 10.17 h)	72.6° 00:30	10.97	43%	103.6°
2045-11-16 Thu	100	—	unknown	19:35–05:35 (good, 10.0 h)	72.6° 00:25	11.0	53%	91.8°
2045-11-17 Fri	100	—	unknown	19:40–05:30 (good, 9.83 h)	72.6° 00:20	11.03	62%	79.9°
2045-11-18 Sat	100	—	unknown	20:45–05:30 (good, 8.75 h)	72.6° 00:15	11.05	71%	68.0°
2045-11-19 Sun	95	—	unknown	23:00–05:25 (good, 6.42 h)	72.6° 00:15	11.08	79%	55.9°
2045-11-20 Mon	87	—	unknown	02:25–05:20 (good, 2.92 h)	72.6° 00:10	11.1	86%	43.6°
2045-11-21 Tue	66	—	unknown	05:05–05:15 (good, 0.17 h)	72.6° 00:05	11.13	93%	31.0°
2045-11-22 Wed	34	—	unknown	01:05–05:20 (marginal, 4.25 h)	72.6° 00:00	11.15	97%	18.1°
2045-11-23 Thu	25	—	unknown	03:05–04:55 (marginal, 1.83 h)	72.6° 23:55	11.18	99%	4.9°
2045-11-24 Fri	24	—	unknown	18:55–20:55 (marginal, 2.0 h)	72.6° 23:55	11.2	100%	8.7°
2045-11-25 Sat	32	—	unknown	18:35–22:40 (marginal, 4.08 h)	72.6° 23:50	11.22	97%	22.5°
2045-11-26 Sun	50	—	unknown	18:35–02:25 (marginal, 7.83 h)	72.6° 23:45	11.24	93%	36.5°
2045-11-27 Mon	85	—	unknown	18:35–22:15 (good, 3.67 h)	72.6° 23:40	11.26	86%	50.6°
2045-11-28 Tue	95	—	unknown	18:35–02:05 (good, 7.5 h)	72.6° 23:35	11.28	77%	64.8°
2045-11-29 Wed	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.6° 23:35	11.3	67%	79.0°
2045-11-30 Thu	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.6° 23:30	11.32	56%	93.1°
2045-12-01 Fri	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.6° 23:25	11.34	44%	107.2°
2045-12-02 Sat	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.6° 23:20	11.35	33%	121.3°
2045-12-03 Sun	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.6° 23:20	11.37	23%	135.2°
2045-12-04 Mon	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.6° 23:15	11.39	14%	149.1°
2045-12-05 Tue	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.6° 23:10	11.4	8%	162.7°
2045-12-06 Wed	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.6° 23:05	11.41	3%	176.2°
2045-12-07 Thu	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.6° 23:00	11.43	0%	170.4°
2045-12-08 Fri	100	—	unknown	18:35–04:10 (good, 9.58 h)	72.6° 23:00	11.44	0%	157.3°
2045-12-09 Sat	100	—	unknown	18:35–04:05 (good, 9.5 h)	72.6° 22:55	11.45	2%	144.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-11-10&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.