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 V1057 Cyg: 06-02 (100), 06-03 (100), 06-04 (100), 06-05 (100), 06-06 (100) — by astronomy; check the weather when the night is within four days.

2038-06-02astronomy score per night — click a bar for that night2038-07-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-06-02 Wed	100	—	unknown	23:20–03:45 (good, 4.42 h)	87.3° 05:35	4.76	0%	93.2°
2038-06-03 Thu	100	—	unknown	23:15–03:45 (good, 4.5 h)	87.3° 05:30	4.72	1%	99.0°
2038-06-04 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 05:25	4.69	4%	104.4°
2038-06-05 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 05:25	4.66	8%	109.4°
2038-06-06 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:20	4.63	15%	113.5°
2038-06-07 Mon	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:15	4.6	23%	116.5°
2038-06-08 Tue	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:10	4.58	33%	118.0°
2038-06-09 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:05	4.55	44%	117.9°
2038-06-10 Thu	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:05	4.53	55%	116.0°
2038-06-11 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 05:00	4.51	66%	112.5°
2038-06-12 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:55	4.49	77%	107.5°
2038-06-13 Sun	87	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:50	4.48	86%	101.5°
2038-06-14 Mon	82	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:45	4.46	93%	94.8°
2038-06-15 Tue	72	—	unknown	23:35–03:40 (good, 4.08 h)	87.3° 04:45	4.45	98%	87.9°
2038-06-16 Wed	64	—	unknown	00:00–03:40 (good, 3.67 h)	87.3° 04:40	4.44	100%	81.1°
2038-06-17 Thu	59	—	unknown	00:00–03:40 (good, 3.67 h)	87.3° 04:35	4.43	99%	75.0°
2038-06-18 Fri	58	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:30	4.43	96%	69.7°
2038-06-19 Sat	78	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:30	4.42	90%	65.6°
2038-06-20 Sun	87	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:25	4.42	83%	63.0°
2038-06-21 Mon	93	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:20	4.42	74%	61.9°
2038-06-22 Tue	97	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:15	4.43	65%	62.2°
2038-06-23 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:10	4.43	56%	64.0°
2038-06-24 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:10	4.44	46%	66.8°
2038-06-25 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:05	4.45	37%	70.6°
2038-06-26 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:00	4.46	28%	75.2°
2038-06-27 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 03:55	4.47	20%	80.3°
2038-06-28 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:50	4.48	13%	85.8°
2038-06-29 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 03:50	4.5	7%	91.5°
2038-06-30 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:45	4.52	3%	97.3°
2038-07-01 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:40	4.54	0%	102.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-06-02&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.