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: 10-06 (100), 10-07 (100), 10-08 (100), 10-09 (100), 10-10 (100) — by astronomy; check the weather when the night is within four days.

2040-10-06astronomy score per night — click a bar for that night2040-11-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-10-06 Sat	100	—	unknown	20:30–03:35 (good, 7.08 h)	87.2° 21:15	9.44	1%	110.5°
2040-10-07 Sun	100	—	unknown	20:25–03:35 (good, 7.17 h)	87.2° 21:15	9.49	3%	105.8°
2040-10-08 Mon	100	—	unknown	20:25–03:30 (good, 7.08 h)	87.2° 21:10	9.54	8%	100.3°
2040-10-09 Tue	100	—	unknown	20:25–03:25 (good, 7.0 h)	87.2° 21:05	9.58	15%	94.2°
2040-10-10 Wed	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.2° 21:00	9.63	24%	87.8°
2040-10-11 Thu	100	—	unknown	20:20–03:20 (good, 7.0 h)	87.2° 21:00	9.67	34%	81.5°
2040-10-12 Fri	100	—	unknown	20:20–03:15 (good, 6.92 h)	87.2° 20:55	9.72	45%	75.6°
2040-10-13 Sat	96	—	unknown	20:15–03:10 (good, 6.92 h)	87.2° 20:50	9.76	56%	70.3°
2040-10-14 Sun	87	—	unknown	20:15–03:05 (good, 6.83 h)	87.2° 20:45	9.8	68%	66.2°
2040-10-15 Mon	69	—	unknown	20:15–02:35 (good, 6.33 h)	87.2° 20:40	9.85	78%	63.5°
2040-10-16 Tue	65	—	unknown	20:10–23:55 (good, 3.75 h)	87.2° 20:40	9.89	87%	62.5°
2040-10-17 Wed	63	—	unknown	20:10–21:00 (good, 0.83 h)	87.2° 20:35	9.93	93%	63.3°
2040-10-18 Thu	62	—	unknown	20:10–21:00 (good, 0.83 h)	87.2° 20:30	9.98	98%	65.9°
2040-10-19 Fri	65	—	unknown	20:10–21:40 (good, 1.5 h)	87.2° 20:25	10.02	100%	69.8°
2040-10-20 Sat	71	—	unknown	20:05–22:50 (good, 2.75 h)	87.2° 20:20	10.06	99%	74.7°
2040-10-21 Sun	76	—	unknown	20:05–23:45 (good, 3.67 h)	87.2° 20:20	10.1	97%	80.2°
2040-10-22 Mon	81	—	unknown	20:05–00:35 (good, 4.5 h)	87.2° 20:15	10.14	92%	86.0°
2040-10-23 Tue	100	—	unknown	20:05–01:30 (good, 5.42 h)	87.2° 20:10	10.18	86%	91.8°
2040-10-24 Wed	100	—	unknown	20:00–02:00 (good, 6.0 h)	87.2° 20:05	10.22	78%	97.4°
2040-10-25 Thu	100	—	unknown	20:00–02:05 (good, 6.08 h)	87.2° 20:00	10.26	69%	102.7°
2040-10-26 Fri	100	—	unknown	20:00–02:05 (good, 6.08 h)	87.2° 20:00	10.3	60%	107.4°
2040-10-27 Sat	100	—	unknown	19:55–02:05 (good, 6.17 h)	87.2° 19:55	10.34	51%	111.3°
2040-10-28 Sun	100	—	unknown	18:55–01:05 (good, 6.17 h)	87.2° 18:50	10.38	42%	114.5°
2040-10-29 Mon	100	—	unknown	18:55–01:05 (good, 6.17 h)	87.2° 18:45	10.41	32%	116.6°
2040-10-30 Tue	100	—	unknown	18:55–01:05 (good, 6.17 h)	87.2° 18:45	10.45	24%	117.4°
2040-10-31 Wed	100	—	unknown	18:55–01:00 (good, 6.08 h)	87.2° 18:40	10.49	16%	117.0°
2040-11-01 Thu	100	—	unknown	18:50–00:55 (good, 6.08 h)	87.2° 18:35	10.52	9%	115.1°
2040-11-02 Fri	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.2° 18:30	10.56	4%	111.9°
2040-11-03 Sat	100	—	unknown	18:50–00:45 (good, 5.92 h)	87.2° 18:25	10.59	1%	107.5°
2040-11-04 Sun	100	—	unknown	18:50–00:45 (good, 5.92 h)	87.2° 18:25	10.63	0%	102.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-10-06&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.