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 V1057 Cyg: 07-31 (100), 08-01 (100), 08-02 (100), 08-03 (100), 08-04 (100) — by astronomy; check the weather when the night is within four days.

2035-07-31astronomy score per night — click a bar for that night2035-08-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-07-31 Tue	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:45	5.78	11%	104.9°
2035-08-01 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:40	5.84	5%	111.7°
2035-08-02 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:35	5.89	1%	117.3°
2035-08-03 Fri	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.3° 01:30	5.95	0%	121.0°
2035-08-04 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.3° 01:30	6.0	2%	122.6°
2035-08-05 Sun	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.3° 01:25	6.06	7%	121.8°
2035-08-06 Mon	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.3° 01:20	6.12	13%	119.0°
2035-08-07 Tue	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.3° 01:15	6.17	22%	114.6°
2035-08-08 Wed	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.3° 01:10	6.23	31%	109.2°
2035-08-09 Thu	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.3° 01:10	6.29	40%	103.2°
2035-08-10 Fri	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.3° 01:05	6.34	50%	96.8°
2035-08-11 Sat	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.3° 01:00	6.4	60%	90.4°
2035-08-12 Sun	100	—	unknown	22:15–04:45 (good, 6.5 h)	87.3° 00:55	6.46	69%	84.0°
2035-08-13 Mon	100	—	unknown	22:15–04:45 (good, 6.5 h)	87.3° 00:55	6.52	77%	77.8°
2035-08-14 Tue	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.3° 00:50	6.57	85%	72.0°
2035-08-15 Wed	97	—	unknown	22:10–04:45 (good, 6.58 h)	87.3° 00:45	6.63	91%	66.9°
2035-08-16 Thu	91	—	unknown	01:00–04:50 (good, 3.83 h)	87.3° 00:40	6.69	96%	62.5°
2035-08-17 Fri	60	—	unknown	03:15–04:05 (good, 0.83 h)	87.3° 00:35	6.75	99%	59.4°
2035-08-18 Sat	60	—	unknown	21:25–04:50 (marginal, 7.42 h)	87.3° 00:35	6.8	100%	57.7°
2035-08-19 Sun	63	—	unknown	22:00–22:35 (good, 0.58 h)	87.3° 00:30	6.86	99%	57.6°
2035-08-20 Mon	67	—	unknown	22:00–23:30 (good, 1.5 h)	87.3° 00:25	6.92	96%	59.3°
2035-08-21 Tue	72	—	unknown	22:00–00:55 (good, 2.92 h)	87.3° 00:20	6.98	91%	62.7°
2035-08-22 Wed	100	—	unknown	21:55–03:15 (good, 5.33 h)	87.3° 00:15	7.03	85%	67.5°
2035-08-23 Thu	100	—	unknown	21:55–04:25 (good, 6.5 h)	87.3° 00:15	7.09	76%	73.5°
2035-08-24 Fri	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:10	7.15	66%	80.3°
2035-08-25 Sat	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:05	7.21	55%	87.6°
2035-08-26 Sun	100	—	unknown	21:50–05:05 (good, 7.25 h)	87.3° 00:00	7.26	44%	95.2°
2035-08-27 Mon	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 00:00	7.32	32%	102.6°
2035-08-28 Tue	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 23:55	7.38	22%	109.5°
2035-08-29 Wed	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.3° 23:50	7.43	13%	115.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-07-31&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.