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: 09-19 (100), 09-20 (100), 09-21 (100), 09-22 (100), 09-23 (100) — by astronomy; check the weather when the night is within four days.

2030-09-19astronomy score per night — click a bar for that night2030-10-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-09-19 Thu	100	—	unknown	21:00–04:30 (good, 7.5 h)	87.3° 22:25	8.58	49%	101.2°
2030-09-20 Fri	100	—	unknown	21:00–04:35 (good, 7.58 h)	87.3° 22:20	8.63	40%	108.1°
2030-09-21 Sat	100	—	unknown	20:55–04:35 (good, 7.67 h)	87.3° 22:20	8.69	30%	114.4°
2030-09-22 Sun	100	—	unknown	20:55–04:30 (good, 7.58 h)	87.3° 22:15	8.74	22%	120.0°
2030-09-23 Mon	100	—	unknown	20:50–04:30 (good, 7.67 h)	87.3° 22:10	8.79	14%	124.4°
2030-09-24 Tue	100	—	unknown	20:50–04:25 (good, 7.58 h)	87.3° 22:05	8.84	8%	127.1°
2030-09-25 Wed	100	—	unknown	20:50–04:20 (good, 7.5 h)	87.3° 22:00	8.89	3%	127.5°
2030-09-26 Thu	100	—	unknown	20:45–04:20 (good, 7.58 h)	87.3° 22:00	8.94	0%	125.5°
2030-09-27 Fri	100	—	unknown	20:45–04:15 (good, 7.5 h)	87.3° 21:55	8.99	0%	121.2°
2030-09-28 Sat	100	—	unknown	20:45–04:10 (good, 7.42 h)	87.3° 21:50	9.04	3%	114.9°
2030-09-29 Sun	100	—	unknown	20:40–04:05 (good, 7.42 h)	87.3° 21:45	9.08	8%	107.3°
2030-09-30 Mon	100	—	unknown	20:40–04:05 (good, 7.42 h)	87.3° 21:45	9.13	16%	98.9°
2030-10-01 Tue	100	—	unknown	20:40–04:00 (good, 7.33 h)	87.3° 21:40	9.18	25%	90.1°
2030-10-02 Wed	100	—	unknown	20:35–03:55 (good, 7.33 h)	87.3° 21:35	9.23	36%	81.4°
2030-10-03 Thu	100	—	unknown	20:35–03:50 (good, 7.25 h)	87.3° 21:30	9.28	47%	73.1°
2030-10-04 Fri	96	—	unknown	20:35–03:45 (good, 7.17 h)	87.3° 21:25	9.32	58%	65.7°
2030-10-05 Sat	88	—	unknown	20:30–03:45 (good, 7.25 h)	87.3° 21:25	9.37	69%	59.5°
2030-10-06 Sun	80	—	unknown	20:30–03:40 (good, 7.17 h)	87.3° 21:20	9.42	79%	55.0°
2030-10-07 Mon	56	—	unknown	20:30–04:05 (marginal, 7.58 h)	87.3° 21:15	9.46	87%	52.6°
2030-10-08 Tue	51	—	unknown	20:25–03:50 (marginal, 7.42 h)	87.3° 21:10	9.51	93%	52.6°
2030-10-09 Wed	48	—	unknown	20:25–03:35 (marginal, 7.17 h)	87.3° 21:05	9.56	97%	54.8°
2030-10-10 Thu	51	—	unknown	20:25–03:25 (marginal, 7.0 h)	87.3° 21:05	9.6	100%	58.8°
2030-10-11 Fri	60	—	unknown	20:20–21:00 (good, 0.67 h)	87.3° 21:00	9.65	100%	64.2°
2030-10-12 Sat	69	—	unknown	20:20–22:30 (good, 2.17 h)	87.3° 20:55	9.69	98%	70.6°
2030-10-13 Sun	76	—	unknown	20:20–00:10 (good, 3.83 h)	87.3° 20:50	9.74	94%	77.5°
2030-10-14 Mon	100	—	unknown	20:15–01:10 (good, 4.92 h)	87.3° 20:50	9.78	89%	84.7°
2030-10-15 Tue	100	—	unknown	20:15–02:10 (good, 5.92 h)	87.3° 20:45	9.82	82%	91.9°
2030-10-16 Wed	100	—	unknown	20:15–02:35 (good, 6.33 h)	87.3° 20:40	9.87	75%	99.1°
2030-10-17 Thu	100	—	unknown	20:10–02:40 (good, 6.5 h)	87.3° 20:35	9.91	66%	106.0°
2030-10-18 Fri	100	—	unknown	20:10–02:40 (good, 6.5 h)	87.3° 20:30	9.95	57%	112.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-09-19&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.