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: 07-11 (100), 07-12 (100), 07-13 (100), 07-14 (100), 07-15 (100) — by astronomy; check the weather when the night is within four days.

2039-07-06astronomy score per night — click a bar for that night2039-08-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-07-06 Wed	60	—	unknown	23:10–03:50 (good, 4.67 h)	87.3° 03:20	4.66	99%	69.5°
2039-07-07 Thu	63	—	unknown	23:10–03:50 (good, 4.67 h)	87.3° 03:20	4.69	95%	65.5°
2039-07-08 Fri	91	—	unknown	23:05–03:50 (good, 4.75 h)	87.3° 03:15	4.73	89%	63.2°
2039-07-09 Sat	96	—	unknown	23:05–03:50 (good, 4.75 h)	87.3° 03:10	4.76	81%	62.5°
2039-07-10 Sun	99	—	unknown	23:05–03:55 (good, 4.83 h)	87.3° 03:05	4.79	72%	63.6°
2039-07-11 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.83	62%	66.0°
2039-07-12 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.3° 03:00	4.87	52%	69.5°
2039-07-13 Wed	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.3° 02:55	4.91	42%	73.8°
2039-07-14 Thu	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:50	4.95	33%	78.7°
2039-07-15 Fri	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:45	4.99	24%	83.9°
2039-07-16 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.03	17%	89.3°
2039-07-17 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:40	5.08	10%	94.8°
2039-07-18 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:35	5.12	5%	100.1°
2039-07-19 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:30	5.17	2%	105.1°
2039-07-20 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:25	5.22	0%	109.5°
2039-07-21 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.3° 02:25	5.27	0%	113.3°
2039-07-22 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.3° 02:20	5.31	3%	115.9°
2039-07-23 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.3° 02:15	5.36	7%	117.4°
2039-07-24 Sun	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.3° 02:10	5.41	13%	117.3°
2039-07-25 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:05	5.47	21%	115.8°
2039-07-26 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.3° 02:05	5.52	30%	112.8°
2039-07-27 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.3° 02:00	5.57	41%	108.4°
2039-07-28 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.3° 01:55	5.62	52%	103.1°
2039-07-29 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.3° 01:50	5.68	64%	97.0°
2039-07-30 Sat	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.73	74%	90.4°
2039-07-31 Sun	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:45	5.78	84%	83.7°
2039-08-01 Mon	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:40	5.84	92%	77.3°
2039-08-02 Tue	75	—	unknown	22:35–04:25 (good, 5.83 h)	87.3° 01:35	5.89	97%	71.6°
2039-08-03 Wed	68	—	unknown	22:30–04:30 (good, 6.0 h)	87.3° 01:30	5.95	100%	67.0°
2039-08-04 Thu	66	—	unknown	22:30–00:50 (good, 2.33 h)	87.3° 01:30	6.01	100%	63.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-07-06&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.