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.

2033-07-01astronomy score per night — click a bar for that night2033-07-30

night of	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-07-01 Fri	—	unknown	—	42.9° 12:20	4.54	25%	77.1°
2033-07-02 Sat	—	unknown	—	42.9° 12:15	4.57	33%	88.1°
2033-07-03 Sun	—	unknown	—	42.9° 12:10	4.59	43%	98.9°
2033-07-04 Mon	—	unknown	—	42.9° 12:05	4.62	52%	109.7°
2033-07-05 Tue	—	unknown	—	42.9° 12:00	4.65	62%	120.3°
2033-07-06 Wed	—	unknown	—	42.9° 11:55	4.68	71%	130.7°
2033-07-07 Thu	—	unknown	—	42.9° 11:50	4.71	79%	140.6°
2033-07-08 Fri	—	unknown	—	42.9° 11:50	4.74	87%	149.3°
2033-07-09 Sat	—	unknown	—	42.9° 11:45	4.78	93%	155.1°
2033-07-10 Sun	—	unknown	—	42.9° 11:40	4.81	97%	155.1°
2033-07-11 Mon	—	unknown	—	42.9° 11:35	4.85	100%	149.1°
2033-07-12 Tue	—	unknown	—	42.9° 11:30	4.89	99%	139.3°
2033-07-13 Wed	—	unknown	—	42.9° 11:30	4.93	97%	127.7°
2033-07-14 Thu	—	unknown	—	42.9° 11:25	4.97	92%	115.1°
2033-07-15 Fri	—	unknown	—	42.9° 11:20	5.01	84%	102.2°
2033-07-16 Sat	—	unknown	—	42.9° 11:15	5.06	75%	89.1°
2033-07-17 Sun	—	unknown	—	42.9° 11:10	5.1	64%	76.0°
2033-07-18 Mon	—	unknown	—	42.9° 11:10	5.15	53%	63.2°
2033-07-19 Tue	—	unknown	—	42.9° 11:05	5.19	41%	50.9°
2033-07-20 Wed	—	unknown	—	42.9° 11:00	5.24	31%	39.5°
2033-07-21 Thu	—	unknown	—	42.9° 10:55	5.29	21%	30.1°
2033-07-22 Fri	—	unknown	—	42.9° 10:50	5.34	13%	24.5°
2033-07-23 Sat	—	unknown	—	42.9° 10:50	5.39	6%	25.4°
2033-07-24 Sun	—	unknown	—	42.9° 10:45	5.44	2%	31.8°
2033-07-25 Mon	—	unknown	—	42.9° 10:40	5.49	0%	41.2°
2033-07-26 Tue	—	unknown	—	42.9° 10:35	5.54	0%	51.7°
2033-07-27 Wed	—	unknown	—	42.9° 10:35	5.59	3%	62.6°
2033-07-28 Thu	—	unknown	—	42.9° 10:30	5.65	7%	73.6°
2033-07-29 Fri	—	unknown	—	42.9° 10:25	5.7	12%	84.6°
2033-07-30 Sat	—	unknown	—	42.9° 10:20	5.76	19%	95.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-07-01&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.