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: 05-24 (100), 05-25 (100), 05-26 (100), 05-27 (100), 05-28 (100) — by astronomy; check the weather when the night is within four days.

2047-05-24astronomy score per night — click a bar for that night2047-06-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-05-24 Fri	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.13	0%	107.8°
2047-05-25 Sat	100	—	unknown	22:50–03:55 (good, 5.08 h)	87.1° 03:45	5.09	1%	112.1°
2047-05-26 Sun	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.04	4%	115.5°
2047-05-27 Mon	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.0	9%	117.7°
2047-05-28 Tue	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.96	16%	118.6°
2047-05-29 Wed	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.91	24%	117.9°
2047-05-30 Thu	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:25	4.87	33%	115.7°
2047-05-31 Fri	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.84	44%	112.0°
2047-06-01 Sat	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.8	55%	107.1°
2047-06-02 Sun	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.76	66%	101.1°
2047-06-03 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.73	77%	94.5°
2047-06-04 Tue	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.7	86%	87.5°
2047-06-05 Wed	79	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:00	4.67	93%	80.5°
2047-06-06 Thu	70	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 03:00	4.64	98%	74.0°
2047-06-07 Fri	60	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.61	100%	68.5°
2047-06-08 Sat	57	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.58	99%	64.3°
2047-06-09 Sun	61	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.56	95%	61.9°
2047-06-10 Mon	92	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.54	90%	61.4°
2047-06-11 Tue	99	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:40	4.52	82%	62.6°
2047-06-12 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.5	73%	65.3°
2047-06-13 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.48	64%	69.2°
2047-06-14 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.47	54%	73.8°
2047-06-15 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.45	44%	79.0°
2047-06-16 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.44	35%	84.5°
2047-06-17 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.44	26%	90.2°
2047-06-18 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	18%	95.8°
2047-06-19 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:05	4.42	12%	101.3°
2047-06-20 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:05	4.42	6%	106.4°
2047-06-21 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	2%	110.9°
2047-06-22 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	0%	114.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-05-24&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.