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: 06-20 (100), 06-21 (100), 06-22 (100), 06-23 (100), 06-24 (100) — by astronomy; check the weather when the night is within four days.

2045-06-20astronomy score per night — click a bar for that night2045-07-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-06-20 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	41%	104.0°
2045-06-21 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	52%	98.6°
2045-06-22 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.43	63%	93.0°
2045-06-23 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	73%	87.3°
2045-06-24 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	82%	81.8°
2045-06-25 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.45	89%	76.7°
2045-06-26 Mon	76	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.46	94%	72.4°
2045-06-27 Tue	68	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.47	98%	68.8°
2045-06-28 Wed	61	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:30	4.49	100%	66.3°
2045-06-29 Thu	60	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:25	4.51	100%	64.9°
2045-06-30 Fri	63	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.53	98%	64.7°
2045-07-01 Sat	69	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.55	94%	65.6°
2045-07-02 Sun	76	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.57	88%	67.6°
2045-07-03 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.59	82%	70.6°
2045-07-04 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.62	74%	74.4°
2045-07-05 Wed	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.65	65%	78.8°
2045-07-06 Thu	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.68	55%	83.8°
2045-07-07 Fri	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:55	4.71	45%	89.0°
2045-07-08 Sat	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.74	35%	94.5°
2045-07-09 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:45	4.78	26%	99.9°
2045-07-10 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.81	17%	105.1°
2045-07-11 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.85	9%	109.6°
2045-07-12 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.89	3%	113.0°
2045-07-13 Thu	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:30	4.93	0%	115.0°
2045-07-14 Fri	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	4.97	0%	115.2°
2045-07-15 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	5.02	3%	113.6°
2045-07-16 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:20	5.06	9%	110.3°
2045-07-17 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:15	5.1	17%	105.7°
2045-07-18 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.15	27%	100.3°
2045-07-19 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.2	38%	94.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-06-20&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.