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: 06-03 (100), 06-04 (100), 06-05 (100), 06-06 (100), 06-07 (100) — by astronomy; check the weather when the night is within four days.

2041-06-03astronomy score per night — click a bar for that night2041-07-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-06-03 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.71	23%	110.2°
2041-06-04 Tue	100	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:05	4.68	32%	107.1°
2041-06-05 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 03:00	4.65	41%	103.3°
2041-06-06 Thu	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.62	50%	99.0°
2041-06-07 Fri	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.6	60%	94.4°
2041-06-08 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.57	69%	89.5°
2041-06-09 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.55	78%	84.5°
2041-06-10 Mon	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:40	4.53	86%	79.6°
2041-06-11 Tue	76	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.51	92%	75.1°
2041-06-12 Wed	67	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:35	4.49	97%	71.1°
2041-06-13 Thu	61	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:30	4.47	100%	68.1°
2041-06-14 Fri	59	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:25	4.46	100%	66.4°
2041-06-15 Sat	66	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:20	4.45	97%	66.2°
2041-06-16 Sun	99	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.44	92%	67.6°
2041-06-17 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.43	84%	70.5°
2041-06-18 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	74%	74.5°
2041-06-19 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:05	4.42	64%	79.5°
2041-06-20 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	52%	84.9°
2041-06-21 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	41%	90.6°
2041-06-22 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.43	30%	96.1°
2041-06-23 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	21%	101.2°
2041-06-24 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	13%	105.8°
2041-06-25 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.45	7%	109.4°
2041-06-26 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.46	2%	112.1°
2041-06-27 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.47	0%	113.6°
2041-06-28 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:30	4.49	0%	113.9°
2041-06-29 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:25	4.5	2%	113.0°
2041-06-30 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.52	6%	111.1°
2041-07-01 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.55	11%	108.3°
2041-07-02 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.57	18%	104.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-06-03&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.