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: 06-09 (100), 06-10 (100), 06-11 (100), 06-12 (100), 06-13 (100) — by astronomy; check the weather when the night is within four days.

2031-06-02astronomy score per night — click a bar for that night2031-07-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2031-06-02 Mon	80	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.77	91%	81.6°
2031-06-03 Tue	70	—	unknown	23:25–03:45 (good, 4.33 h)	87.1° 03:10	4.73	96%	74.4°
2031-06-04 Wed	59	—	unknown	00:05–03:45 (good, 3.67 h)	87.1° 03:05	4.7	100%	67.7°
2031-06-05 Thu	52	—	unknown	03:05–03:40 (good, 0.58 h)	87.1° 03:00	4.67	100%	62.4°
2031-06-06 Fri	53	—	unknown	23:05–01:05 (good, 2.0 h)	87.1° 03:00	4.64	97%	58.9°
2031-06-07 Sat	60	—	unknown	23:05–02:30 (good, 3.42 h)	87.1° 02:55	4.61	91%	57.7°
2031-06-08 Sun	95	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.59	83%	58.9°
2031-06-09 Mon	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.56	74%	62.3°
2031-06-10 Tue	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.54	63%	67.3°
2031-06-11 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:40	4.52	52%	73.3°
2031-06-12 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.5	41%	79.9°
2031-06-13 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.48	31%	86.7°
2031-06-14 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.47	22%	93.5°
2031-06-15 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.46	14%	100.1°
2031-06-16 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.44	8%	106.2°
2031-06-17 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.44	4%	111.6°
2031-06-18 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	1%	116.1°
2031-06-19 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:05	4.43	0%	119.6°
2031-06-20 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:05	4.42	1%	121.7°
2031-06-21 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	4%	122.3°
2031-06-22 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	8%	121.4°
2031-06-23 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	14%	119.0°
2031-06-24 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.43	21%	115.3°
2031-06-25 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	30%	110.5°
2031-06-26 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.45	39%	104.8°
2031-06-27 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.46	49%	98.4°
2031-06-28 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:30	4.48	60%	91.6°
2031-06-29 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:30	4.5	70%	84.4°
2031-06-30 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:25	4.51	80%	77.2°
2031-07-01 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.53	88%	70.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-06-02&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.