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: 10-12 (100), 10-13 (100), 10-14 (100), 10-15 (100), 10-16 (100) — by astronomy; check the weather when the night is within four days.

2041-10-08astronomy score per night — click a bar for that night2041-11-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-10-08 Tue	63	—	unknown	20:25–21:05 (good, 0.67 h)	87.2° 21:10	9.53	99%	63.5°
2041-10-09 Wed	66	—	unknown	20:25–21:40 (good, 1.25 h)	87.2° 21:05	9.57	100%	67.1°
2041-10-10 Thu	71	—	unknown	20:20–23:00 (good, 2.67 h)	87.2° 21:00	9.62	98%	72.1°
2041-10-11 Fri	77	—	unknown	20:20–00:20 (good, 4.0 h)	87.2° 21:00	9.66	94%	78.0°
2041-10-12 Sat	100	—	unknown	20:20–01:20 (good, 5.0 h)	87.2° 20:55	9.71	87%	84.3°
2041-10-13 Sun	100	—	unknown	20:15–02:25 (good, 6.17 h)	87.2° 20:50	9.75	78%	90.7°
2041-10-14 Mon	100	—	unknown	20:15–02:40 (good, 6.42 h)	87.2° 20:45	9.79	69%	96.9°
2041-10-15 Tue	100	—	unknown	20:15–02:45 (good, 6.5 h)	87.2° 20:45	9.84	60%	102.5°
2041-10-16 Wed	100	—	unknown	20:15–02:50 (good, 6.58 h)	87.2° 20:40	9.88	50%	107.6°
2041-10-17 Thu	100	—	unknown	20:10–02:50 (good, 6.67 h)	87.2° 20:35	9.92	40%	111.8°
2041-10-18 Fri	100	—	unknown	20:10–02:50 (good, 6.67 h)	87.2° 20:30	9.97	31%	115.1°
2041-10-19 Sat	100	—	unknown	20:10–02:45 (good, 6.58 h)	87.2° 20:25	10.01	22%	117.3°
2041-10-20 Sun	100	—	unknown	20:05–02:45 (good, 6.67 h)	87.2° 20:25	10.05	15%	118.2°
2041-10-21 Mon	100	—	unknown	20:05–02:40 (good, 6.58 h)	87.2° 20:20	10.09	9%	117.8°
2041-10-22 Tue	100	—	unknown	20:05–02:35 (good, 6.5 h)	87.2° 20:15	10.13	4%	116.2°
2041-10-23 Wed	100	—	unknown	20:05–02:30 (good, 6.42 h)	87.2° 20:10	10.17	1%	113.3°
2041-10-24 Thu	100	—	unknown	20:00–02:30 (good, 6.5 h)	87.2° 20:05	10.21	0%	109.4°
2041-10-25 Fri	100	—	unknown	20:00–02:25 (good, 6.42 h)	87.2° 20:05	10.25	1%	104.6°
2041-10-26 Sat	100	—	unknown	20:00–02:20 (good, 6.33 h)	87.2° 20:00	10.29	3%	99.1°
2041-10-27 Sun	100	—	unknown	19:00–01:15 (good, 6.25 h)	87.2° 18:55	10.33	8%	93.2°
2041-10-28 Mon	100	—	unknown	18:55–01:10 (good, 6.25 h)	87.2° 18:50	10.37	15%	87.0°
2041-10-29 Tue	100	—	unknown	18:55–01:10 (good, 6.25 h)	87.2° 18:50	10.4	23%	80.9°
2041-10-30 Wed	100	—	unknown	18:55–01:05 (good, 6.17 h)	87.2° 18:45	10.44	33%	75.1°
2041-10-31 Thu	95	—	unknown	18:55–01:00 (good, 6.08 h)	87.2° 18:40	10.48	44%	69.9°
2041-11-01 Fri	86	—	unknown	18:50–00:55 (good, 6.08 h)	87.2° 18:35	10.51	55%	65.7°
2041-11-02 Sat	73	—	unknown	18:50–00:30 (good, 5.67 h)	87.2° 18:30	10.55	66%	62.9°
2041-11-03 Sun	66	—	unknown	18:50–22:55 (good, 4.08 h)	87.2° 18:30	10.59	76%	61.8°
2041-11-04 Mon	58	—	unknown	18:50–20:05 (good, 1.25 h)	87.2° 18:25	10.62	86%	62.6°
2041-11-05 Tue	53	—	unknown	18:50–19:20 (good, 0.5 h)	87.2° 18:20	10.66	93%	65.4°
2041-11-06 Wed	54	—	unknown	18:45–19:40 (good, 0.92 h)	87.2° 18:15	10.69	98%	69.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-10-08&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.