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: 12-06 (100), 12-07 (100), 12-08 (100), 12-09 (100), 12-10 (100) — by astronomy; check the weather when the night is within four days.

2037-12-06astronomy score per night — click a bar for that night2038-01-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2037-12-17 Thu	72	—	unknown	03:15–03:35 (good, 0.33 h)	72.5° 22:20	11.5	79%	28.8°
2037-12-18 Fri	44	—	unknown	18:35–03:45 (marginal, 9.17 h)	72.5° 22:20	11.5	87%	17.5°
2037-12-19 Sat	31	—	unknown	22:20–03:25 (marginal, 5.08 h)	72.5° 22:15	11.51	93%	8.7°
2037-12-20 Sun	25	—	unknown	18:35–20:45 (marginal, 2.17 h)	72.5° 22:10	11.51	97%	12.5°
2037-12-21 Mon	25	—	unknown	18:35–21:00 (marginal, 2.42 h)	72.5° 22:05	11.51	100%	23.8°
2037-12-22 Tue	36	—	unknown	18:35–22:50 (marginal, 4.25 h)	72.5° 22:05	11.51	100%	36.5°
2037-12-23 Wed	58	—	unknown	18:40–02:45 (marginal, 8.08 h)	72.5° 22:00	11.5	98%	49.6°
2037-12-24 Thu	93	—	unknown	18:40–22:05 (good, 3.42 h)	72.5° 21:55	11.5	94%	63.1°
2037-12-25 Fri	100	—	unknown	18:40–00:50 (good, 6.17 h)	72.5° 21:50	11.5	87%	76.8°
2037-12-26 Sat	100	—	unknown	18:40–02:25 (good, 7.75 h)	72.5° 21:45	11.49	78%	90.7°
2037-12-27 Sun	100	—	unknown	18:40–02:40 (good, 8.0 h)	72.5° 21:45	11.49	68%	104.6°
2037-12-28 Mon	100	—	unknown	18:40–02:45 (good, 8.08 h)	72.5° 21:40	11.48	57%	118.5°
2037-12-29 Tue	100	—	unknown	18:40–02:40 (good, 8.0 h)	72.5° 21:35	11.48	46%	132.5°
2037-12-30 Wed	100	—	unknown	18:40–02:40 (good, 8.0 h)	72.5° 21:30	11.47	35%	146.2°
2037-12-31 Thu	100	—	unknown	18:45–02:40 (good, 7.92 h)	72.5° 21:25	11.46	24%	159.6°
2038-01-01 Fri	100	—	unknown	18:45–02:35 (good, 7.83 h)	72.5° 21:25	11.45	15%	170.6°
2038-01-02 Sat	100	—	unknown	18:45–02:30 (good, 7.75 h)	72.5° 21:20	11.44	8%	167.7°
2038-01-03 Sun	100	—	unknown	18:45–02:25 (good, 7.67 h)	72.5° 21:15	11.43	3%	155.7°
2038-01-04 Mon	100	—	unknown	18:45–02:25 (good, 7.67 h)	72.5° 21:10	11.41	0%	142.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-12-06&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.