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: 10-21 (100), 10-22 (100), 10-23 (100), 10-24 (100), 10-25 (100) — by astronomy; check the weather when the night is within four days.

2044-10-21astronomy score per night — click a bar for that night2044-11-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-10-21 Fri	100	—	unknown	20:05–02:40 (good, 6.58 h)	87.2° 20:20	10.1	1%	109.0°
2044-10-22 Sat	100	—	unknown	20:05–02:35 (good, 6.5 h)	87.2° 20:15	10.14	4%	102.8°
2044-10-23 Sun	100	—	unknown	20:05–02:30 (good, 6.42 h)	87.2° 20:10	10.18	9%	96.4°
2044-10-24 Mon	100	—	unknown	20:00–02:25 (good, 6.42 h)	87.2° 20:05	10.22	15%	89.8°
2044-10-25 Tue	100	—	unknown	20:00–02:25 (good, 6.42 h)	87.2° 20:05	10.26	23%	83.3°
2044-10-26 Wed	100	—	unknown	20:00–02:20 (good, 6.33 h)	87.2° 20:00	10.3	31%	77.1°
2044-10-27 Thu	99	—	unknown	19:55–02:15 (good, 6.33 h)	87.2° 19:55	10.34	40%	71.3°
2044-10-28 Fri	91	—	unknown	19:55–02:10 (good, 6.25 h)	87.2° 19:50	10.38	49%	66.2°
2044-10-29 Sat	83	—	unknown	19:55–02:05 (good, 6.17 h)	87.2° 19:45	10.41	59%	62.0°
2044-10-30 Sun	70	—	unknown	18:55–00:35 (good, 5.67 h)	87.2° 18:45	10.45	68%	58.9°
2044-10-31 Mon	63	—	unknown	18:55–22:10 (good, 3.25 h)	87.2° 18:40	10.49	77%	57.3°
2044-11-01 Tue	54	—	unknown	18:50–01:20 (marginal, 6.5 h)	87.2° 18:35	10.52	85%	57.4°
2044-11-02 Wed	48	—	unknown	18:50–01:05 (marginal, 6.25 h)	87.2° 18:30	10.56	92%	59.4°
2044-11-03 Thu	47	—	unknown	18:50–00:50 (marginal, 6.0 h)	87.2° 18:25	10.6	97%	63.3°
2044-11-04 Fri	51	—	unknown	18:50–19:20 (good, 0.5 h)	87.2° 18:25	10.63	99%	68.7°
2044-11-05 Sat	62	—	unknown	18:45–20:55 (good, 2.17 h)	87.2° 18:20	10.66	100%	75.4°
2044-11-06 Sun	75	—	unknown	18:45–22:00 (good, 3.25 h)	87.2° 18:15	10.7	97%	82.8°
2044-11-07 Mon	82	—	unknown	18:45–23:10 (good, 4.42 h)	87.2° 18:10	10.73	92%	90.7°
2044-11-08 Tue	100	—	unknown	18:45–00:00 (good, 5.25 h)	87.2° 18:05	10.76	84%	98.6°
2044-11-09 Wed	100	—	unknown	18:45–00:05 (good, 5.33 h)	87.2° 18:05	10.8	75%	106.0°
2044-11-10 Thu	100	—	unknown	18:45–00:10 (good, 5.42 h)	87.2° 18:00	10.83	65%	112.5°
2044-11-11 Fri	100	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:55	10.86	53%	117.8°
2044-11-12 Sat	100	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:50	10.89	42%	121.3°
2044-11-13 Sun	100	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:50	10.92	32%	122.9°
2044-11-14 Mon	100	—	unknown	18:40–00:05 (good, 5.42 h)	87.2° 17:45	10.95	22%	122.4°
2044-11-15 Tue	100	—	unknown	18:40–00:00 (good, 5.33 h)	87.2° 17:40	10.98	14%	120.0°
2044-11-16 Wed	100	—	unknown	18:40–23:55 (good, 5.25 h)	87.2° 17:35	11.01	8%	116.0°
2044-11-17 Thu	100	—	unknown	18:40–23:50 (good, 5.17 h)	87.2° 17:30	11.03	3%	110.8°
2044-11-18 Fri	100	—	unknown	18:35–23:50 (good, 5.25 h)	87.2° 17:30	11.06	1%	104.8°
2044-11-19 Sat	100	—	unknown	18:35–23:45 (good, 5.17 h)	87.2° 17:25	11.09	0%	98.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-10-21&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.