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.

2038-06-20astronomy score per night — click a bar for that night2038-07-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-06-20 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	83%	69.8°
2038-06-21 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	74%	74.6°
2038-06-22 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.43	65%	79.9°
2038-06-23 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	56%	85.5°
2038-06-24 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	46%	91.2°
2038-06-25 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.45	37%	96.7°
2038-06-26 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.46	28%	102.1°
2038-06-27 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.47	20%	107.0°
2038-06-28 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:30	4.48	13%	111.3°
2038-06-29 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:25	4.5	7%	114.8°
2038-06-30 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:25	4.52	3%	117.2°
2038-07-01 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.54	0%	118.2°
2038-07-02 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.56	0%	117.8°
2038-07-03 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.59	2%	115.8°
2038-07-04 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.61	6%	112.4°
2038-07-05 Mon	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:05	4.64	13%	107.7°
2038-07-06 Tue	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.67	21%	102.1°
2038-07-07 Wed	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 00:55	4.7	31%	95.8°
2038-07-08 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.73	42%	89.2°
2038-07-09 Fri	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.77	53%	82.6°
2038-07-10 Sat	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.8	64%	76.3°
2038-07-11 Sun	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.84	75%	70.7°
2038-07-12 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.88	84%	66.1°
2038-07-13 Tue	96	—	unknown	23:00–03:55 (good, 4.92 h)	87.1° 00:30	4.92	92%	63.1°
2038-07-14 Wed	63	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:30	4.96	97%	61.8°
2038-07-15 Thu	57	—	unknown	01:30–04:00 (good, 2.5 h)	87.1° 00:25	5.0	100%	62.3°
2038-07-16 Fri	61	—	unknown	23:00–03:20 (good, 4.33 h)	87.1° 00:20	5.05	100%	64.5°
2038-07-17 Sat	69	—	unknown	22:55–03:25 (good, 4.5 h)	87.1° 00:15	5.09	98%	68.1°
2038-07-18 Sun	76	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 00:10	5.14	93%	72.7°
2038-07-19 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.18	87%	77.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-06-20&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.