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.

2034-06-21astronomy score per night — click a bar for that night2034-07-20

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-06-21 Wed	—	unknown	—	42.9° 13:00	4.42	34%	79.2°
2034-06-22 Thu	—	unknown	—	42.9° 12:55	4.43	43%	90.7°
2034-06-23 Fri	—	unknown	—	42.9° 12:50	4.43	53%	101.9°
2034-06-24 Sat	—	unknown	—	42.9° 12:50	4.44	63%	112.8°
2034-06-25 Sun	—	unknown	—	42.9° 12:45	4.45	72%	123.3°
2034-06-26 Mon	—	unknown	—	42.9° 12:40	4.46	80%	133.5°
2034-06-27 Tue	—	unknown	—	42.9° 12:35	4.47	87%	142.9°
2034-06-28 Wed	—	unknown	—	42.9° 12:30	4.48	92%	150.9°
2034-06-29 Thu	—	unknown	—	42.9° 12:30	4.5	97%	155.7°
2034-06-30 Fri	—	unknown	—	42.9° 12:25	4.52	99%	155.4°
2034-07-01 Sat	—	unknown	—	42.9° 12:20	4.54	100%	149.9°
2034-07-02 Sun	—	unknown	—	42.9° 12:15	4.56	98%	141.1°
2034-07-03 Mon	—	unknown	—	42.9° 12:10	4.59	95%	130.7°
2034-07-04 Tue	—	unknown	—	42.9° 12:10	4.61	89%	119.4°
2034-07-05 Wed	—	unknown	—	42.9° 12:00	4.64	82%	107.5°
2034-07-06 Thu	—	unknown	—	42.9° 12:00	4.67	73%	95.2°
2034-07-07 Fri	—	unknown	—	42.9° 11:50	4.7	63%	82.7°
2034-07-08 Sat	—	unknown	—	42.9° 11:50	4.73	52%	70.1°
2034-07-09 Sun	—	unknown	—	42.9° 11:45	4.77	40%	57.5°
2034-07-10 Mon	—	unknown	—	42.9° 11:40	4.8	29%	45.2°
2034-07-11 Tue	—	unknown	—	42.9° 11:35	4.84	19%	34.1°
2034-07-12 Wed	—	unknown	—	42.9° 11:35	4.88	11%	25.8°
2034-07-13 Thu	—	unknown	—	42.9° 11:30	4.92	5%	23.9°
2034-07-14 Fri	—	unknown	—	42.9° 11:25	4.96	1%	29.6°
2034-07-15 Sat	—	unknown	—	42.9° 11:20	5.0	0%	39.5°
2034-07-16 Sun	—	unknown	—	42.9° 11:15	5.04	2%	51.0°
2034-07-17 Mon	—	unknown	—	42.9° 11:15	5.09	6%	63.0°
2034-07-18 Tue	—	unknown	—	42.9° 11:10	5.13	12%	74.9°
2034-07-19 Wed	—	unknown	—	42.9° 11:05	5.18	19%	86.7°
2034-07-20 Thu	—	unknown	—	42.9° 11:00	5.23	28%	98.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-06-21&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.