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: 08-07 (100), 08-08 (100), 08-09 (100), 08-10 (100), 08-11 (100) — by astronomy; check the weather when the night is within four days.

2037-08-07astronomy score per night — click a bar for that night2037-09-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-08-07 Fri	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.3° 01:15	6.2	16%	102.6°
2037-08-08 Sat	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.3° 01:10	6.26	9%	108.5°
2037-08-09 Sun	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.3° 01:05	6.32	3%	113.6°
2037-08-10 Mon	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.3° 01:00	6.37	0%	117.3°
2037-08-11 Tue	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.3° 01:00	6.43	0%	119.2°
2037-08-12 Wed	100	—	unknown	22:15–04:45 (good, 6.5 h)	87.3° 00:55	6.49	3%	119.0°
2037-08-13 Thu	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.3° 00:50	6.55	9%	116.6°
2037-08-14 Fri	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.3° 00:45	6.6	17%	112.5°
2037-08-15 Sat	100	—	unknown	22:10–04:50 (good, 6.67 h)	87.3° 00:45	6.66	27%	107.0°
2037-08-16 Sun	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.3° 00:40	6.72	38%	100.8°
2037-08-17 Mon	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.3° 00:35	6.78	49%	94.2°
2037-08-18 Tue	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.3° 00:30	6.83	60%	87.6°
2037-08-19 Wed	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.3° 00:25	6.89	70%	81.3°
2037-08-20 Thu	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.3° 00:25	6.95	79%	75.4°
2037-08-21 Fri	100	—	unknown	21:55–04:55 (good, 7.0 h)	87.3° 00:20	7.01	86%	70.3°
2037-08-22 Sat	93	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:15	7.06	92%	66.0°
2037-08-23 Sun	64	—	unknown	01:05–05:00 (good, 3.92 h)	87.3° 00:10	7.12	97%	62.9°
2037-08-24 Mon	62	—	unknown	21:50–22:30 (good, 0.67 h)	87.3° 00:05	7.18	99%	61.0°
2037-08-25 Tue	63	—	unknown	21:50–22:40 (good, 0.83 h)	87.3° 00:05	7.24	100%	60.6°
2037-08-26 Wed	67	—	unknown	21:45–23:15 (good, 1.5 h)	87.3° 00:00	7.29	99%	61.5°
2037-08-27 Thu	71	—	unknown	21:45–00:15 (good, 2.5 h)	87.3° 23:55	7.35	96%	63.8°
2037-08-28 Fri	75	—	unknown	21:45–01:40 (good, 3.92 h)	87.3° 23:50	7.41	91%	67.1°
2037-08-29 Sat	100	—	unknown	21:40–03:10 (good, 5.5 h)	87.3° 23:50	7.46	85%	71.4°
2037-08-30 Sun	100	—	unknown	21:40–04:00 (good, 6.33 h)	87.3° 23:45	7.52	78%	76.4°
2037-08-31 Mon	100	—	unknown	21:35–05:00 (good, 7.42 h)	87.3° 23:40	7.57	69%	81.9°
2037-09-01 Tue	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.3° 23:35	7.63	60%	87.9°
2037-09-02 Wed	100	—	unknown	21:35–05:15 (good, 7.67 h)	87.3° 23:30	7.69	50%	94.0°
2037-09-03 Thu	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.3° 23:30	7.74	40%	100.2°
2037-09-04 Fri	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.3° 23:25	7.8	29%	106.1°
2037-09-05 Sat	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.3° 23:20	7.85	20%	111.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-08-07&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.