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: 11-29 (100), 11-30 (100), 12-01 (100), 12-02 (100), 12-03 (100) — by astronomy; check the weather when the night is within four days.

2045-11-20astronomy score per night — click a bar for that night2045-12-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2045-12-10 Sun	100	—	unknown	18:35–04:00 (good, 9.42 h)	72.6° 22:50	11.46	6%	132.0°
2045-12-11 Mon	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.6° 22:45	11.47	12%	119.7°
2045-12-12 Tue	100	—	unknown	18:35–03:55 (good, 9.33 h)	72.6° 22:40	11.47	18%	107.6°
2045-12-13 Wed	100	—	unknown	18:35–03:50 (good, 9.25 h)	72.6° 22:40	11.48	26%	95.7°
2045-12-14 Thu	100	—	unknown	18:35–03:45 (good, 9.17 h)	72.6° 22:35	11.49	35%	83.8°
2045-12-15 Fri	100	—	unknown	18:35–03:40 (good, 9.08 h)	72.6° 22:30	11.49	44%	72.0°
2045-12-16 Sat	98	—	unknown	18:35–03:40 (good, 9.08 h)	72.6° 22:25	11.5	54%	60.1°
2045-12-17 Sun	90	—	unknown	20:00–03:35 (good, 7.58 h)	72.6° 22:25	11.5	63%	48.0°
2045-12-18 Mon	82	—	unknown	00:10–02:30 (good, 2.33 h)	72.6° 22:20	11.5	72%	35.7°
2045-12-19 Tue	50	—	unknown	18:35–03:45 (marginal, 9.17 h)	72.6° 22:15	11.51	81%	23.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-11-20&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.