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: 06-29 (100), 06-30 (100), 07-01 (100), 07-02 (100), 07-08 (100) — by astronomy; check the weather when the night is within four days.

2039-06-29astronomy score per night — click a bar for that night2039-07-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-06-29 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:30	4.5	55%	86.3°
2039-06-30 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:25	4.51	66%	80.3°
2039-07-01 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.53	77%	74.6°
2039-07-02 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.56	86%	69.6°
2039-07-03 Sun	72	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.58	93%	65.9°
2039-07-04 Mon	62	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.61	98%	63.8°
2039-07-05 Tue	57	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.63	100%	63.6°
2039-07-06 Wed	62	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.66	99%	65.3°
2039-07-07 Thu	72	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 00:55	4.69	95%	68.6°
2039-07-08 Fri	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.73	89%	73.2°
2039-07-09 Sat	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.76	81%	78.5°
2039-07-10 Sun	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.79	72%	84.1°
2039-07-11 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.83	62%	89.8°
2039-07-12 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.87	52%	95.4°
2039-07-13 Wed	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.1° 00:35	4.91	42%	100.6°
2039-07-14 Thu	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:30	4.95	33%	105.4°
2039-07-15 Fri	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	4.99	24%	109.5°
2039-07-16 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:20	5.03	17%	112.8°
2039-07-17 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:15	5.08	10%	115.2°
2039-07-18 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:15	5.12	5%	116.4°
2039-07-19 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.17	2%	116.4°
2039-07-20 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.22	0%	115.2°
2039-07-21 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 00:00	5.27	0%	112.8°
2039-07-22 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.31	3%	109.2°
2039-07-23 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.36	7%	104.7°
2039-07-24 Sun	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 23:50	5.41	13%	99.5°
2039-07-25 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:45	5.47	21%	93.8°
2039-07-26 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.52	30%	87.9°
2039-07-27 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.57	41%	81.9°
2039-07-28 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.62	52%	76.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-06-29&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.