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: 08-10 (100), 08-11 (100), 08-22 (100), 08-23 (100), 08-24 (100) — by astronomy; check the weather when the night is within four days.

2035-08-10astronomy score per night — click a bar for that night2035-09-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-08-10 Fri	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.34	50%	70.4°
2035-08-11 Sat	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.1° 22:40	6.4	60%	65.5°
2035-08-12 Sun	97	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:35	6.46	69%	61.6°
2035-08-13 Mon	91	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:30	6.52	77%	58.9°
2035-08-14 Tue	85	—	unknown	22:10–04:25 (good, 6.25 h)	87.1° 22:25	6.57	85%	57.6°
2035-08-15 Wed	76	—	unknown	00:00–02:15 (good, 2.25 h)	87.1° 22:25	6.63	91%	57.9°
2035-08-16 Thu	58	—	unknown	22:05–04:50 (marginal, 6.75 h)	87.1° 22:20	6.69	96%	59.7°
2035-08-17 Fri	58	—	unknown	22:05–22:30 (good, 0.42 h)	87.1° 22:15	6.75	99%	63.0°
2035-08-18 Sat	62	—	unknown	22:05–23:35 (good, 1.5 h)	87.1° 22:10	6.8	100%	67.5°
2035-08-19 Sun	69	—	unknown	22:00–01:00 (good, 3.0 h)	87.1° 22:05	6.86	99%	73.1°
2035-08-20 Mon	75	—	unknown	22:00–01:40 (good, 3.67 h)	87.1° 22:05	6.92	96%	79.4°
2035-08-21 Tue	80	—	unknown	22:00–02:30 (good, 4.5 h)	87.1° 22:00	6.98	91%	86.2°
2035-08-22 Wed	100	—	unknown	21:55–03:15 (good, 5.33 h)	87.1° 21:55	7.03	85%	93.3°
2035-08-23 Thu	100	—	unknown	21:55–03:30 (good, 5.58 h)	87.1° 21:50	7.09	76%	100.3°
2035-08-24 Fri	100	—	unknown	21:50–03:30 (good, 5.67 h)	87.1° 21:50	7.15	66%	107.0°
2035-08-25 Sat	100	—	unknown	21:50–03:35 (good, 5.75 h)	87.1° 21:45	7.21	55%	113.1°
2035-08-26 Sun	100	—	unknown	21:50–03:35 (good, 5.75 h)	87.1° 21:40	7.26	44%	118.0°
2035-08-27 Mon	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:35	7.32	32%	121.3°
2035-08-28 Tue	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:30	7.38	22%	122.5°
2035-08-29 Wed	100	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:30	7.43	13%	121.4°
2035-08-30 Thu	100	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:25	7.49	6%	118.2°
2035-08-31 Fri	100	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:20	7.55	2%	113.1°
2035-09-01 Sat	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.6	0%	106.8°
2035-09-02 Sun	100	—	unknown	21:35–03:10 (good, 5.58 h)	87.1° 21:10	7.66	1%	99.8°
2035-09-03 Mon	100	—	unknown	21:30–03:10 (good, 5.67 h)	87.1° 21:10	7.71	4%	92.5°
2035-09-04 Tue	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.77	10%	85.4°
2035-09-05 Wed	100	—	unknown	21:30–03:00 (good, 5.5 h)	87.1° 21:00	7.82	17%	78.6°
2035-09-06 Thu	100	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 20:55	7.88	25%	72.4°
2035-09-07 Fri	100	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:55	7.93	34%	67.1°
2035-09-08 Sat	99	—	unknown	21:20–02:50 (good, 5.5 h)	87.1° 20:50	7.99	43%	62.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-08-10&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.