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 North America Nebula: 06-10 (100), 06-11 (100), 06-12 (100), 06-13 (100), 06-14 (100) — by astronomy; check the weather when the night is within four days.

2043-06-10astronomy score per night — click a bar for that night2043-07-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-06-10 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:05	4.54	16%	113.1°
2043-06-11 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:00	4.52	25%	117.2°
2043-06-12 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:55	4.5	35%	119.8°
2043-06-13 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:50	4.48	45%	120.6°
2043-06-14 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:50	4.47	55%	119.8°
2043-06-15 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:45	4.45	64%	117.6°
2043-06-16 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:40	4.44	73%	114.2°
2043-06-17 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:35	4.43	81%	109.8°
2043-06-18 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:35	4.43	88%	104.7°
2043-06-19 Fri	86	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.42	93%	99.0°
2043-06-20 Sat	81	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:25	4.42	97%	93.1°
2043-06-21 Sun	75	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:20	4.42	99%	87.0°
2043-06-22 Mon	68	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.42	100%	80.9°
2043-06-23 Tue	63	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	98%	75.0°
2043-06-24 Wed	63	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	94%	69.6°
2043-06-25 Thu	83	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.44	89%	65.1°
2043-06-26 Fri	91	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.45	82%	61.6°
2043-06-27 Sat	94	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.47	73%	59.6°
2043-06-28 Sun	97	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.48	63%	59.4°
2043-06-29 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:50	4.5	52%	61.0°
2043-06-30 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:45	4.51	41%	64.5°
2043-07-01 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.53	30%	69.5°
2043-07-02 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.56	20%	75.8°
2043-07-03 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.58	11%	82.9°
2043-07-04 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.61	5%	90.4°
2043-07-05 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:25	4.63	1%	97.9°
2043-07-06 Mon	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.66	0%	104.9°
2043-07-07 Tue	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.69	2%	111.1°
2043-07-08 Wed	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:15	4.73	6%	115.9°
2043-07-09 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:10	4.76	13%	119.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-06-10&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.