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: 06-11 (100), 06-12 (100), 06-13 (100), 06-14 (100), 06-15 (100) — by astronomy; check the weather when the night is within four days.

2042-06-04astronomy score per night — click a bar for that night2042-07-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-06-04 Wed	65	—	unknown	23:45–03:45 (good, 4.0 h)	87.2° 05:25	4.69	99%	84.4°
2042-06-05 Thu	63	—	unknown	23:40–03:40 (good, 4.0 h)	87.2° 05:25	4.66	95%	78.3°
2042-06-06 Fri	75	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:20	4.63	90%	72.6°
2042-06-07 Sat	84	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:15	4.6	82%	67.7°
2042-06-08 Sun	91	—	unknown	23:05–03:40 (good, 4.58 h)	87.3° 05:10	4.58	73%	63.9°
2042-06-09 Mon	94	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:05	4.55	62%	61.5°
2042-06-10 Tue	97	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:05	4.53	51%	61.0°
2042-06-11 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 05:00	4.51	40%	62.3°
2042-06-12 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:55	4.49	29%	65.5°
2042-06-13 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:50	4.48	19%	70.2°
2042-06-14 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:50	4.46	11%	76.0°
2042-06-15 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:45	4.45	5%	82.5°
2042-06-16 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:40	4.44	1%	89.4°
2042-06-17 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 04:35	4.43	0%	96.1°
2042-06-18 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.43	2%	102.5°
2042-06-19 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.42	6%	108.1°
2042-06-20 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:25	4.42	11%	112.8°
2042-06-21 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:20	4.42	18%	116.3°
2042-06-22 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:15	4.42	26%	118.5°
2042-06-23 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	36%	119.2°
2042-06-24 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.44	45%	118.5°
2042-06-25 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:05	4.44	54%	116.6°
2042-06-26 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:00	4.46	64%	113.4°
2042-06-27 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 03:55	4.47	72%	109.3°
2042-06-28 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:50	4.48	81%	104.3°
2042-06-29 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 03:50	4.5	88%	98.7°
2042-06-30 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:45	4.52	94%	92.7°
2042-07-01 Tue	79	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:40	4.54	98%	86.5°
2042-07-02 Wed	72	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.56	100%	80.2°
2042-07-03 Thu	65	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.59	99%	74.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-06-04&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.