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: 08-28 (100), 08-29 (100), 08-30 (100), 09-09 (100), 09-10 (100) — by astronomy; check the weather when the night is within four days.

2047-08-28astronomy score per night — click a bar for that night2047-09-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-08-28 Wed	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.38	59%	88.5°
2047-08-29 Thu	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:50	7.44	70%	80.3°
2047-08-30 Fri	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:45	7.49	80%	72.5°
2047-08-31 Sat	93	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:40	7.55	88%	65.6°
2047-09-01 Sun	85	—	unknown	01:10–05:10 (good, 4.0 h)	87.1° 23:40	7.61	94%	59.9°
2047-09-02 Mon	57	—	unknown	21:35–05:15 (marginal, 7.67 h)	87.2° 23:35	7.66	98%	55.8°
2047-09-03 Tue	56	—	unknown	21:30–05:15 (marginal, 7.75 h)	87.2° 23:30	7.72	100%	53.6°
2047-09-04 Wed	58	—	unknown	21:30–05:15 (marginal, 7.75 h)	87.2° 23:25	7.77	100%	53.4°
2047-09-05 Thu	61	—	unknown	21:30–21:45 (good, 0.25 h)	87.2° 23:20	7.83	97%	55.3°
2047-09-06 Fri	67	—	unknown	21:25–22:50 (good, 1.42 h)	87.2° 23:20	7.88	93%	58.8°
2047-09-07 Sat	73	—	unknown	21:25–00:25 (good, 3.0 h)	87.2° 23:15	7.94	88%	63.7°
2047-09-08 Sun	79	—	unknown	21:20–02:25 (good, 5.08 h)	87.2° 23:10	7.99	81%	69.5°
2047-09-09 Mon	100	—	unknown	21:20–03:30 (good, 6.17 h)	87.2° 23:05	8.05	73%	75.9°
2047-09-10 Tue	100	—	unknown	21:20–04:40 (good, 7.33 h)	87.1° 23:00	8.1	64%	82.7°
2047-09-11 Wed	100	—	unknown	21:15–04:55 (good, 7.67 h)	87.2° 23:00	8.16	55%	89.8°
2047-09-12 Thu	100	—	unknown	21:15–05:00 (good, 7.75 h)	87.2° 22:55	8.21	46%	97.0°
2047-09-13 Fri	100	—	unknown	21:10–05:00 (good, 7.83 h)	87.2° 22:50	8.26	36%	104.1°
2047-09-14 Sat	100	—	unknown	21:10–05:00 (good, 7.83 h)	87.2° 22:45	8.32	27%	110.9°
2047-09-15 Sun	100	—	unknown	21:10–05:00 (good, 7.83 h)	87.1° 22:45	8.37	18%	117.2°
2047-09-16 Mon	100	—	unknown	21:05–05:00 (good, 7.92 h)	87.2° 22:40	8.42	10%	122.3°
2047-09-17 Tue	100	—	unknown	21:05–04:55 (good, 7.83 h)	87.2° 22:35	8.47	5%	125.7°
2047-09-18 Wed	100	—	unknown	21:00–04:50 (good, 7.83 h)	87.2° 22:30	8.52	1%	126.8°
2047-09-19 Thu	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.2° 22:25	8.58	0%	125.2°
2047-09-20 Fri	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.2° 22:25	8.63	2%	121.0°
2047-09-21 Sat	100	—	unknown	20:55–04:40 (good, 7.75 h)	87.2° 22:20	8.68	7%	114.8°
2047-09-22 Sun	100	—	unknown	20:55–04:35 (good, 7.67 h)	87.2° 22:15	8.73	14%	107.2°
2047-09-23 Mon	100	—	unknown	20:55–04:30 (good, 7.58 h)	87.2° 22:10	8.78	23%	98.9°
2047-09-24 Tue	100	—	unknown	20:50–04:30 (good, 7.67 h)	87.1° 22:05	8.83	34%	90.4°
2047-09-25 Wed	100	—	unknown	20:50–04:25 (good, 7.58 h)	87.2° 22:05	8.88	45%	82.0°
2047-09-26 Thu	100	—	unknown	20:45–04:20 (good, 7.58 h)	87.2° 22:00	8.93	56%	74.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-08-28&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.