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: 06-06 (100), 06-07 (100), 06-08 (100), 06-09 (100), 06-10 (100) — by astronomy; check the weather when the night is within four days.

2041-06-06astronomy score per night — click a bar for that night2041-07-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-06-06 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:20	4.62	50%	117.8°
2041-06-07 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:15	4.6	60%	116.8°
2041-06-08 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:10	4.57	69%	114.5°
2041-06-09 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:05	4.55	78%	111.0°
2041-06-10 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:00	4.53	86%	106.5°
2041-06-11 Tue	86	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:00	4.51	92%	101.1°
2041-06-12 Wed	80	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:55	4.49	97%	95.0°
2041-06-13 Thu	73	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:50	4.47	100%	88.6°
2041-06-14 Fri	66	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:45	4.46	100%	82.1°
2041-06-15 Sat	63	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:40	4.45	97%	75.8°
2041-06-16 Sun	79	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:40	4.44	92%	70.3°
2041-06-17 Mon	89	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:35	4.43	84%	65.9°
2041-06-18 Tue	93	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.43	74%	63.1°
2041-06-19 Wed	97	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:25	4.42	64%	62.1°
2041-06-20 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:25	4.42	52%	62.9°
2041-06-21 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:20	4.42	41%	65.5°
2041-06-22 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	30%	69.5°
2041-06-23 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	21%	74.4°
2041-06-24 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.44	13%	80.1°
2041-06-25 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.45	7%	86.0°
2041-06-26 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.46	2%	92.1°
2041-06-27 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.47	0%	97.9°
2041-06-28 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:50	4.49	0%	103.4°
2041-06-29 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:45	4.5	2%	108.2°
2041-06-30 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:45	4.52	6%	112.3°
2041-07-01 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.55	11%	115.4°
2041-07-02 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.57	18%	117.3°
2041-07-03 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.59	26%	118.0°
2041-07-04 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.62	34%	117.4°
2041-07-05 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:25	4.65	44%	115.6°

Download: CSV · JSON

💡 API

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