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.

2037-06-06astronomy score per night — click a bar for that night2037-07-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-06-06 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:20	4.62	41%	63.5°
2037-06-07 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:15	4.6	32%	66.8°
2037-06-08 Mon	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:10	4.57	23%	71.1°
2037-06-09 Tue	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:05	4.55	15%	76.3°
2037-06-10 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.2° 05:00	4.53	9%	82.1°
2037-06-11 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 05:00	4.51	4%	88.3°
2037-06-12 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:55	4.49	1%	94.8°
2037-06-13 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:50	4.47	0%	101.2°
2037-06-14 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:45	4.46	2%	107.2°
2037-06-15 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:40	4.45	6%	112.5°
2037-06-16 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:40	4.44	13%	116.5°
2037-06-17 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:35	4.43	21%	118.8°
2037-06-18 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:30	4.43	32%	119.3°
2037-06-19 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 04:25	4.42	43%	117.8°
2037-06-20 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:25	4.42	54%	114.5°
2037-06-21 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:20	4.42	65%	109.8°
2037-06-22 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	76%	104.0°
2037-06-23 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	85%	97.7°
2037-06-24 Wed	82	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.44	92%	91.1°
2037-06-25 Thu	74	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.45	97%	84.5°
2037-06-26 Fri	64	—	unknown	23:40–03:40 (good, 4.0 h)	87.2° 04:00	4.46	99%	78.2°
2037-06-27 Sat	58	—	unknown	23:55–03:40 (good, 3.75 h)	87.2° 03:55	4.47	100%	72.6°
2037-06-28 Sun	55	—	unknown	23:35–03:40 (good, 4.08 h)	87.2° 03:50	4.49	98%	67.8°
2037-06-29 Mon	57	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:45	4.51	95%	64.2°
2037-06-30 Tue	82	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:45	4.52	89%	61.7°
2037-07-01 Wed	92	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.55	83%	60.7°
2037-07-02 Thu	96	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.57	75%	61.1°
2037-07-03 Fri	99	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.59	66%	62.8°
2037-07-04 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.62	57%	65.7°
2037-07-05 Sun	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:25	4.65	47%	69.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-06-06&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.