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: 06-17 (100), 06-18 (100), 06-19 (100), 06-20 (100), 06-21 (100) — by astronomy; check the weather when the night is within four days.

2042-06-17astronomy score per night — click a bar for that night2042-07-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-06-17 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.43	0%	112.5°
2042-06-18 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	2%	113.3°
2042-06-19 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:05	4.42	6%	112.8°
2042-06-20 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	11%	111.0°
2042-06-21 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	18%	108.3°
2042-06-22 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	26%	104.8°
2042-06-23 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	36%	100.7°
2042-06-24 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	45%	96.3°
2042-06-25 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	54%	91.6°
2042-06-26 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.46	64%	87.0°
2042-06-27 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.47	72%	82.4°
2042-06-28 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:30	4.48	81%	78.0°
2042-06-29 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:25	4.5	88%	74.0°
2042-06-30 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:25	4.52	94%	70.7°
2042-07-01 Tue	70	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.54	98%	68.3°
2042-07-02 Wed	63	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.56	100%	66.9°
2042-07-03 Thu	63	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.59	99%	66.8°
2042-07-04 Fri	69	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.61	97%	68.1°
2042-07-05 Sat	76	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:05	4.64	92%	70.7°
2042-07-06 Sun	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.67	84%	74.5°
2042-07-07 Mon	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 00:55	4.7	75%	79.2°
2042-07-08 Tue	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.73	65%	84.4°
2042-07-09 Wed	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.77	54%	90.0°
2042-07-10 Thu	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.8	42%	95.6°
2042-07-11 Fri	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.84	31%	100.8°
2042-07-12 Sat	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.88	21%	105.5°
2042-07-13 Sun	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.1° 00:30	4.92	13%	109.2°
2042-07-14 Mon	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:30	4.96	6%	111.8°
2042-07-15 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	5.0	2%	113.2°
2042-07-16 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:20	5.05	0%	113.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-06-17&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.