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

2037-05-31astronomy score per night — click a bar for that night2037-06-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-05-31 Sun	86	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.82	92%	60.4°
2037-06-01 Mon	95	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.78	85%	62.2°
2037-06-02 Tue	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.75	77%	65.2°
2037-06-03 Wed	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.72	69%	69.4°
2037-06-04 Thu	100	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:05	4.68	60%	74.3°
2037-06-05 Fri	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 03:00	4.65	50%	79.7°
2037-06-06 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.62	41%	85.4°
2037-06-07 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.6	32%	91.4°
2037-06-08 Mon	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.57	23%	97.3°
2037-06-09 Tue	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.55	15%	103.1°
2037-06-10 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:40	4.53	9%	108.6°
2037-06-11 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.51	4%	113.3°
2037-06-12 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.49	1%	117.1°
2037-06-13 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.47	0%	119.3°
2037-06-14 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.46	2%	119.8°
2037-06-15 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.45	6%	118.4°
2037-06-16 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.44	13%	115.2°
2037-06-17 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.43	21%	110.4°
2037-06-18 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	32%	104.5°
2037-06-19 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:05	4.42	43%	97.8°
2037-06-20 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	54%	90.8°
2037-06-21 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	65%	83.8°
2037-06-22 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.43	76%	77.2°
2037-06-23 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	85%	71.2°
2037-06-24 Wed	68	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	92%	66.2°
2037-06-25 Thu	58	—	unknown	00:55–03:40 (good, 2.75 h)	87.1° 01:40	4.45	97%	62.6°
2037-06-26 Fri	52	—	unknown	02:35–03:40 (good, 1.08 h)	87.1° 01:40	4.46	99%	60.5°
2037-06-27 Sat	51	—	unknown	23:15–23:55 (good, 0.67 h)	87.1° 01:35	4.47	100%	60.2°
2037-06-28 Sun	57	—	unknown	23:10–01:20 (good, 2.17 h)	87.1° 01:30	4.49	98%	61.4°
2037-06-29 Mon	65	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:25	4.51	95%	64.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-05-31&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.