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: 10-26 (100), 10-27 (100), 10-28 (100), 10-29 (100), 10-30 (100) — by astronomy; check the weather when the night is within four days.

2037-10-25astronomy score per night — click a bar for that night2037-11-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-10-25 Sun	78	—	unknown	19:00–23:00 (good, 4.0 h)	87.2° 19:05	10.25	97%	84.6°
2037-10-26 Mon	100	—	unknown	19:00–23:50 (good, 4.83 h)	87.2° 19:00	10.29	93%	90.5°
2037-10-27 Tue	100	—	unknown	19:00–00:40 (good, 5.67 h)	87.2° 18:55	10.33	87%	96.6°
2037-10-28 Wed	100	—	unknown	18:55–00:50 (good, 5.92 h)	87.2° 18:50	10.37	79%	102.4°
2037-10-29 Thu	100	—	unknown	18:55–00:50 (good, 5.92 h)	87.2° 18:50	10.4	70%	107.9°
2037-10-30 Fri	100	—	unknown	18:55–00:55 (good, 6.0 h)	87.2° 18:45	10.44	60%	112.6°
2037-10-31 Sat	100	—	unknown	18:55–00:55 (good, 6.0 h)	87.2° 18:40	10.48	50%	116.3°
2037-11-01 Sun	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:35	10.51	38%	118.5°
2037-11-02 Mon	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.55	28%	118.9°
2037-11-03 Tue	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.58	18%	117.3°
2037-11-04 Wed	100	—	unknown	18:50–00:45 (good, 5.92 h)	87.2° 18:25	10.62	10%	113.9°
2037-11-05 Thu	100	—	unknown	18:50–00:40 (good, 5.83 h)	87.2° 18:20	10.65	4%	108.8°
2037-11-06 Fri	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.2° 18:15	10.69	1%	102.6°
2037-11-07 Sat	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.2° 18:10	10.72	0%	95.7°
2037-11-08 Sun	100	—	unknown	18:45–00:30 (good, 5.75 h)	87.2° 18:10	10.75	3%	88.7°
2037-11-09 Mon	100	—	unknown	18:45–00:25 (good, 5.67 h)	87.2° 18:05	10.79	8%	81.9°
2037-11-10 Tue	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:00	10.82	15%	75.7°
2037-11-11 Wed	100	—	unknown	18:40–00:15 (good, 5.58 h)	87.2° 17:55	10.85	23%	70.4°
2037-11-12 Thu	93	—	unknown	18:40–00:15 (good, 5.58 h)	87.2° 17:55	10.88	32%	66.1°
2037-11-13 Fri	87	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:50	10.91	42%	63.1°
2037-11-14 Sat	80	—	unknown	18:40–00:05 (good, 5.42 h)	87.2° 17:45	10.94	52%	61.5°
2037-11-15 Sun	73	—	unknown	18:40–23:35 (good, 4.92 h)	87.2° 17:40	10.97	61%	61.2°
2037-11-16 Mon	65	—	unknown	18:40–22:40 (good, 4.0 h)	87.2° 17:35	11.0	70%	62.2°
2037-11-17 Tue	58	—	unknown	18:40–21:10 (good, 2.5 h)	87.2° 17:35	11.02	78%	64.5°
2037-11-18 Wed	54	—	unknown	18:35–20:30 (good, 1.92 h)	87.2° 17:30	11.05	86%	68.0°
2037-11-19 Thu	53	—	unknown	18:35–20:25 (good, 1.83 h)	87.2° 17:25	11.08	92%	72.3°
2037-11-20 Fri	55	—	unknown	18:35–20:35 (good, 2.0 h)	87.2° 17:20	11.1	96%	77.3°
2037-11-21 Sat	60	—	unknown	18:35–20:55 (good, 2.33 h)	87.2° 17:15	11.13	99%	82.9°
2037-11-22 Sun	68	—	unknown	18:35–21:30 (good, 2.92 h)	87.2° 17:15	11.15	100%	88.9°
2037-11-23 Mon	77	—	unknown	18:35–22:10 (good, 3.58 h)	87.2° 17:10	11.18	99%	94.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-10-25&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.