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: 06-24 (100), 06-25 (100), 06-26 (100), 06-27 (100), 06-28 (100) — by astronomy; check the weather when the night is within four days.

2039-06-24astronomy score per night — click a bar for that night2039-07-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-06-24 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	10%	113.9°
2039-06-25 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.44	16%	116.3°
2039-06-26 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.45	24%	117.3°
2039-06-27 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.47	34%	116.9°
2039-06-28 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.48	44%	115.0°
2039-06-29 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:50	4.5	55%	111.7°
2039-06-30 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:45	4.51	66%	107.0°
2039-07-01 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.53	77%	101.3°
2039-07-02 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.56	86%	94.8°
2039-07-03 Sun	81	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.58	93%	88.0°
2039-07-04 Mon	75	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.61	98%	81.2°
2039-07-05 Tue	65	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:25	4.63	100%	74.9°
2039-07-06 Wed	60	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.66	99%	69.6°
2039-07-07 Thu	63	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.69	95%	65.6°
2039-07-08 Fri	91	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:15	4.73	89%	63.2°
2039-07-09 Sat	96	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:10	4.76	81%	62.6°
2039-07-10 Sun	99	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:05	4.79	72%	63.6°
2039-07-11 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.83	62%	66.0°
2039-07-12 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.87	52%	69.5°
2039-07-13 Wed	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.2° 02:55	4.91	42%	73.8°
2039-07-14 Thu	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:50	4.95	33%	78.7°
2039-07-15 Fri	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	4.99	24%	83.9°
2039-07-16 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.03	17%	89.3°
2039-07-17 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:40	5.08	10%	94.7°
2039-07-18 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:35	5.12	5%	100.0°
2039-07-19 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.17	2%	105.0°
2039-07-20 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:25	5.22	0%	109.5°
2039-07-21 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:25	5.27	0%	113.2°
2039-07-22 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:20	5.31	3%	115.9°
2039-07-23 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:15	5.36	7%	117.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-06-24&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.