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 Vega: 05-31 (100), 06-01 (100), 06-02 (100), 06-03 (100), 06-04 (100) — by astronomy; check the weather when the night is within four days.

2035-05-31astronomy score per night — click a bar for that night2035-06-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-05-31 Thu	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.84	33%	84.2°
2035-06-01 Fri	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.8	24%	91.5°
2035-06-02 Sat	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.77	15%	99.0°
2035-06-03 Sun	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.73	7%	106.2°
2035-06-04 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.7	2%	112.8°
2035-06-05 Tue	100	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:00	4.67	0%	118.1°
2035-06-06 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 03:00	4.64	1%	121.5°
2035-06-07 Thu	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.61	5%	122.4°
2035-06-08 Fri	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.59	12%	120.9°
2035-06-09 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.56	20%	117.2°
2035-06-10 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.54	30%	112.0°
2035-06-11 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:40	4.52	40%	105.9°
2035-06-12 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.5	51%	99.2°
2035-06-13 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.48	61%	92.4°
2035-06-14 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.47	71%	85.7°
2035-06-15 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.46	79%	79.2°
2035-06-16 Sat	78	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.44	87%	73.2°
2035-06-17 Sun	67	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:15	4.44	92%	67.9°
2035-06-18 Mon	57	—	unknown	01:15–03:40 (good, 2.42 h)	87.1° 02:10	4.43	97%	63.5°
2035-06-19 Tue	50	—	unknown	03:00–03:40 (good, 0.67 h)	87.1° 02:05	4.43	99%	60.1°
2035-06-20 Wed	46	—	unknown	23:15–03:40 (marginal, 4.42 h)	87.1° 02:05	4.42	100%	58.1°
2035-06-21 Thu	49	—	unknown	23:15–23:50 (good, 0.58 h)	87.1° 02:00	4.42	99%	57.6°
2035-06-22 Fri	55	—	unknown	23:15–01:05 (good, 1.83 h)	87.1° 01:55	4.42	96%	58.7°
2035-06-23 Sat	65	—	unknown	23:15–03:15 (good, 4.0 h)	87.1° 01:50	4.43	91%	61.2°
2035-06-24 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.43	85%	65.1°
2035-06-25 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	78%	70.0°
2035-06-26 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.45	69%	75.9°
2035-06-27 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.47	59%	82.4°
2035-06-28 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:30	4.48	48%	89.3°
2035-06-29 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:30	4.5	38%	96.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-05-31&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.