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: 07-04 (100), 07-05 (100), 07-06 (100), 07-07 (100), 07-08 (100) — by astronomy; check the weather when the night is within four days.

2037-06-24astronomy score per night — click a bar for that night2037-07-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-06-24 Wed	82	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:05	4.44	92%	91.1°
2037-06-25 Thu	74	—	unknown	23:15–03:40 (good, 4.42 h)	87.3° 04:05	4.45	97%	84.5°
2037-06-26 Fri	64	—	unknown	23:40–03:40 (good, 4.0 h)	87.3° 04:00	4.46	99%	78.2°
2037-06-27 Sat	58	—	unknown	23:55–03:40 (good, 3.75 h)	87.3° 03:55	4.47	100%	72.6°
2037-06-28 Sun	55	—	unknown	23:35–03:40 (good, 4.08 h)	87.3° 03:50	4.49	98%	67.8°
2037-06-29 Mon	57	—	unknown	23:10–03:40 (good, 4.5 h)	87.3° 03:50	4.51	95%	64.1°
2037-06-30 Tue	82	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:45	4.52	89%	61.7°
2037-07-01 Wed	92	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:40	4.55	83%	60.6°
2037-07-02 Thu	96	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:35	4.57	75%	61.0°
2037-07-03 Fri	99	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:30	4.59	66%	62.7°
2037-07-04 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.3° 03:30	4.62	57%	65.7°
2037-07-05 Sun	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.3° 03:25	4.65	47%	69.6°
2037-07-06 Mon	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.3° 03:20	4.68	38%	74.5°
2037-07-07 Tue	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.3° 03:15	4.71	28%	80.0°
2037-07-08 Wed	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.3° 03:10	4.74	20%	86.0°
2037-07-09 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.3° 03:10	4.78	12%	92.4°
2037-07-10 Fri	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.3° 03:05	4.81	6%	98.9°
2037-07-11 Sat	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.3° 03:00	4.85	2%	105.1°
2037-07-12 Sun	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.3° 02:55	4.89	0%	110.7°
2037-07-13 Mon	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.3° 02:50	4.93	1%	115.3°
2037-07-14 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:50	4.97	5%	118.3°
2037-07-15 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:45	5.01	11%	119.4°
2037-07-16 Thu	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.3° 02:40	5.06	19%	118.4°
2037-07-17 Fri	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:35	5.1	29%	115.4°
2037-07-18 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:35	5.15	40%	110.9°
2037-07-19 Sun	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:30	5.19	52%	105.3°
2037-07-20 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.3° 02:25	5.24	63%	99.1°
2037-07-21 Tue	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.3° 02:20	5.29	73%	92.6°
2037-07-22 Wed	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.3° 02:15	5.34	82%	86.1°
2037-07-23 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.3° 02:15	5.39	90%	79.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-06-24&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.