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: 06-24 (100), 06-25 (100), 06-26 (100), 06-27 (100), 06-28 (100) — by astronomy; check the weather when the night is within four days.

2035-06-16astronomy score per night — click a bar for that night2035-07-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-06-16 Sat	78	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.44	87%	73.2°
2035-06-17 Sun	67	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:15	4.44	92%	67.9°
2035-06-18 Mon	57	—	unknown	01:15–03:40 (good, 2.42 h)	87.1° 02:10	4.43	97%	63.5°
2035-06-19 Tue	50	—	unknown	03:00–03:40 (good, 0.67 h)	87.1° 02:05	4.43	99%	60.1°
2035-06-20 Wed	46	—	unknown	23:15–03:40 (marginal, 4.42 h)	87.1° 02:05	4.42	100%	58.1°
2035-06-21 Thu	49	—	unknown	23:15–23:50 (good, 0.58 h)	87.1° 02:00	4.42	99%	57.6°
2035-06-22 Fri	55	—	unknown	23:15–01:05 (good, 1.83 h)	87.1° 01:55	4.42	96%	58.7°
2035-06-23 Sat	65	—	unknown	23:15–03:15 (good, 4.0 h)	87.1° 01:50	4.43	91%	61.2°
2035-06-24 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.43	85%	65.1°
2035-06-25 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	78%	70.0°
2035-06-26 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.45	69%	75.9°
2035-06-27 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.47	59%	82.4°
2035-06-28 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:30	4.48	48%	89.3°
2035-06-29 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:30	4.5	38%	96.5°
2035-06-30 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:25	4.51	27%	103.7°
2035-07-01 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.53	17%	110.4°
2035-07-02 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.56	9%	116.2°
2035-07-03 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.58	4%	120.3°
2035-07-04 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.61	0%	122.3°
2035-07-05 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.63	0%	121.8°
2035-07-06 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.66	4%	118.8°
2035-07-07 Sat	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 00:55	4.69	9%	114.0°
2035-07-08 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.73	17%	108.0°
2035-07-09 Mon	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.76	26%	101.2°
2035-07-10 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.79	36%	94.2°
2035-07-11 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.83	46%	87.3°
2035-07-12 Thu	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.87	56%	80.7°
2035-07-13 Fri	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.1° 00:35	4.91	66%	74.5°
2035-07-14 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:30	4.95	75%	69.0°
2035-07-15 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	4.99	82%	64.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-06-16&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.