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.

2047-06-19astronomy score per night — click a bar for that night2047-07-18

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-06-19 Wed	—	unknown	—	42.9° 13:10	4.42	12%	46.4°
2047-06-20 Thu	—	unknown	—	42.9° 13:05	4.42	6%	38.6°
2047-06-21 Fri	—	unknown	—	42.9° 13:00	4.42	2%	32.9°
2047-06-22 Sat	—	unknown	—	42.9° 12:55	4.42	0%	30.6°
2047-06-23 Sun	—	unknown	—	42.9° 12:55	4.43	0%	32.7°
2047-06-24 Mon	—	unknown	—	42.9° 12:50	4.44	2%	38.7°
2047-06-25 Tue	—	unknown	—	42.9° 12:45	4.44	6%	47.3°
2047-06-26 Wed	—	unknown	—	42.9° 12:40	4.45	13%	57.3°
2047-06-27 Thu	—	unknown	—	42.9° 12:35	4.47	21%	68.3°
2047-06-28 Fri	—	unknown	—	42.9° 12:35	4.48	30%	79.8°
2047-06-29 Sat	—	unknown	—	42.9° 12:30	4.5	41%	91.7°
2047-06-30 Sun	—	unknown	—	42.9° 12:25	4.52	52%	103.7°
2047-07-01 Mon	—	unknown	—	42.9° 12:20	4.54	64%	115.6°
2047-07-02 Tue	—	unknown	—	42.9° 12:15	4.56	74%	127.1°
2047-07-03 Wed	—	unknown	—	42.9° 12:15	4.58	84%	137.5°
2047-07-04 Thu	—	unknown	—	42.9° 12:10	4.61	92%	145.6°
2047-07-05 Fri	—	unknown	—	42.9° 12:05	4.64	97%	149.3°
2047-07-06 Sat	—	unknown	—	42.9° 12:00	4.67	100%	147.2°
2047-07-07 Sun	—	unknown	—	42.9° 11:55	4.7	100%	140.4°
2047-07-08 Mon	—	unknown	—	42.9° 11:50	4.73	97%	131.1°
2047-07-09 Tue	—	unknown	—	42.9° 11:45	4.76	92%	120.7°
2047-07-10 Wed	—	unknown	—	42.9° 11:40	4.8	86%	109.9°
2047-07-11 Thu	—	unknown	—	42.9° 11:40	4.83	78%	99.1°
2047-07-12 Fri	—	unknown	—	42.9° 11:35	4.87	70%	88.5°
2047-07-13 Sat	—	unknown	—	42.9° 11:30	4.91	60%	78.1°
2047-07-14 Sun	—	unknown	—	42.9° 11:25	4.95	51%	68.0°
2047-07-15 Mon	—	unknown	—	42.9° 11:20	5.0	41%	58.3°
2047-07-16 Tue	—	unknown	—	42.9° 11:20	5.04	32%	49.1°
2047-07-17 Wed	—	unknown	—	42.9° 11:15	5.08	24%	40.9°
2047-07-18 Thu	—	unknown	—	42.9° 11:10	5.13	16%	34.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-06-19&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.