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: 12-01 (100), 12-02 (100), 12-03 (100), 12-04 (100), 12-05 (100) — by astronomy; check the weather when the night is within four days.

2035-12-01astronomy score per night — click a bar for that night2035-12-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-12-01 Sat	100	—	unknown	18:35–04:40 (good, 10.08 h)	72.5° 23:25	11.33	4%	146.0°
2035-12-02 Sun	100	—	unknown	18:35–04:35 (good, 10.0 h)	72.5° 23:25	11.34	9%	134.5°
2035-12-03 Mon	100	—	unknown	18:35–04:30 (good, 9.92 h)	72.5° 23:20	11.36	15%	123.0°
2035-12-04 Tue	100	—	unknown	18:35–04:25 (good, 9.83 h)	72.5° 23:15	11.38	22%	111.3°
2035-12-05 Wed	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.5° 23:10	11.39	30%	99.6°
2035-12-06 Thu	100	—	unknown	18:35–04:20 (good, 9.75 h)	72.5° 23:10	11.4	39%	87.7°
2035-12-07 Fri	100	—	unknown	18:35–04:15 (good, 9.67 h)	72.5° 23:05	11.42	49%	75.7°
2035-12-08 Sat	100	—	unknown	18:45–04:10 (good, 9.42 h)	72.5° 23:00	11.43	59%	63.3°
2035-12-09 Sun	93	—	unknown	20:40–04:05 (good, 7.42 h)	72.5° 22:55	11.44	69%	50.6°
2035-12-10 Mon	84	—	unknown	01:15–02:55 (good, 1.67 h)	72.5° 22:50	11.45	78%	37.5°
2035-12-11 Tue	54	—	unknown	18:35–04:25 (marginal, 9.83 h)	72.5° 22:50	11.46	87%	24.4°
2035-12-12 Wed	34	—	unknown	18:35–04:00 (marginal, 9.42 h)	72.5° 22:45	11.47	93%	12.3°
2035-12-13 Thu	27	—	unknown	18:35–21:00 (marginal, 2.42 h)	72.5° 22:40	11.48	98%	11.2°
2035-12-14 Fri	29	—	unknown	18:35–21:30 (marginal, 2.92 h)	72.5° 22:35	11.48	100%	23.3°
2035-12-15 Sat	44	—	unknown	18:35–00:25 (marginal, 5.83 h)	72.5° 22:30	11.49	99%	37.7°
2035-12-16 Sun	88	—	unknown	18:35–20:45 (good, 2.17 h)	72.5° 22:30	11.5	94%	52.5°
2035-12-17 Mon	97	—	unknown	18:35–00:20 (good, 5.75 h)	72.5° 22:25	11.5	88%	67.2°
2035-12-18 Tue	100	—	unknown	18:35–02:15 (good, 7.67 h)	72.5° 22:20	11.5	79%	81.7°
2035-12-19 Wed	100	—	unknown	18:35–03:05 (good, 8.5 h)	72.5° 22:15	11.51	69%	95.8°
2035-12-20 Thu	100	—	unknown	18:35–03:15 (good, 8.67 h)	72.5° 22:15	11.51	58%	109.5°
2035-12-21 Fri	100	—	unknown	18:35–03:15 (good, 8.67 h)	72.5° 22:10	11.51	47%	122.7°
2035-12-22 Sat	100	—	unknown	18:35–03:10 (good, 8.58 h)	72.5° 22:05	11.51	37%	135.5°
2035-12-23 Sun	100	—	unknown	18:40–03:10 (good, 8.5 h)	72.5° 22:00	11.51	28%	147.8°
2035-12-24 Mon	100	—	unknown	18:40–03:10 (good, 8.5 h)	72.5° 21:55	11.5	19%	159.4°
2035-12-25 Tue	100	—	unknown	18:40–03:05 (good, 8.42 h)	72.5° 21:55	11.5	12%	168.9°
2035-12-26 Wed	100	—	unknown	18:40–03:00 (good, 8.33 h)	72.5° 21:50	11.5	7%	169.1°
2035-12-27 Thu	100	—	unknown	18:40–02:55 (good, 8.25 h)	72.5° 21:45	11.49	3%	159.9°
2035-12-28 Fri	100	—	unknown	18:40–02:50 (good, 8.17 h)	72.5° 21:40	11.49	0%	148.9°
2035-12-29 Sat	100	—	unknown	18:40–02:50 (good, 8.17 h)	72.5° 21:35	11.48	0%	137.5°
2035-12-30 Sun	100	—	unknown	18:40–02:45 (good, 8.08 h)	72.5° 21:35	11.47	2%	126.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-12-01&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.