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: 08-22 (100), 08-23 (100), 08-24 (100), 08-25 (100), 08-26 (100) — by astronomy; check the weather when the night is within four days.

2035-08-21astronomy score per night — click a bar for that night2035-09-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-08-21 Tue	72	—	unknown	22:00–00:55 (good, 2.92 h)	87.2° 00:20	6.98	91%	62.8°
2035-08-22 Wed	100	—	unknown	21:55–03:15 (good, 5.33 h)	87.2° 00:15	7.03	85%	67.6°
2035-08-23 Thu	100	—	unknown	21:55–04:25 (good, 6.5 h)	87.2° 00:15	7.09	76%	73.5°
2035-08-24 Fri	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.2° 00:10	7.15	66%	80.3°
2035-08-25 Sat	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.2° 00:05	7.21	55%	87.6°
2035-08-26 Sun	100	—	unknown	21:50–05:05 (good, 7.25 h)	87.2° 00:00	7.26	44%	95.2°
2035-08-27 Mon	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.32	32%	102.6°
2035-08-28 Tue	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.38	22%	109.4°
2035-08-29 Wed	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:50	7.43	13%	115.4°
2035-08-30 Thu	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:45	7.49	6%	119.8°
2035-08-31 Fri	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:40	7.55	2%	122.2°
2035-09-01 Sat	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.2° 23:40	7.6	0%	122.3°
2035-09-02 Sun	100	—	unknown	21:35–05:15 (good, 7.67 h)	87.2° 23:35	7.66	1%	120.3°
2035-09-03 Mon	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:30	7.71	4%	116.5°
2035-09-04 Tue	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:25	7.77	10%	111.4°
2035-09-05 Wed	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:20	7.82	17%	105.4°
2035-09-06 Thu	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:20	7.88	25%	99.1°
2035-09-07 Fri	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:15	7.93	34%	92.5°
2035-09-08 Sat	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.2° 23:10	7.99	43%	86.1°
2035-09-09 Sun	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.2° 23:05	8.04	53%	79.8°
2035-09-10 Mon	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.2° 23:00	8.1	62%	73.9°
2035-09-11 Tue	100	—	unknown	21:15–05:20 (good, 8.08 h)	87.2° 23:00	8.15	71%	68.5°
2035-09-12 Wed	93	—	unknown	21:15–05:15 (good, 8.0 h)	87.2° 22:55	8.2	80%	63.9°
2035-09-13 Thu	86	—	unknown	21:10–05:10 (good, 8.0 h)	87.2° 22:50	8.26	87%	60.3°
2035-09-14 Fri	80	—	unknown	04:30–05:05 (good, 0.58 h)	87.2° 22:45	8.31	93%	58.1°
2035-09-15 Sat	58	—	unknown	21:10–05:30 (marginal, 8.33 h)	87.2° 22:45	8.36	97%	57.5°
2035-09-16 Sun	60	—	unknown	21:05–21:10 (good, 0.08 h)	87.2° 22:40	8.42	100%	58.7°
2035-09-17 Mon	64	—	unknown	21:05–21:55 (good, 0.83 h)	87.2° 22:35	8.47	100%	61.6°
2035-09-18 Tue	69	—	unknown	21:00–23:05 (good, 2.08 h)	87.2° 22:30	8.52	98%	66.1°
2035-09-19 Wed	75	—	unknown	21:00–01:05 (good, 4.08 h)	87.2° 22:25	8.57	94%	71.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-08-21&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.