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 Vega: 08-18 (100), 08-19 (100), 08-20 (100), 08-21 (100), 08-22 (100) — by astronomy; check the weather when the night is within four days.

2030-08-15astronomy score per night — click a bar for that night2030-09-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-08-15 Thu	74	—	unknown	22:10–01:40 (good, 3.5 h)	87.1° 22:20	6.64	92%	76.0°
2030-08-16 Fri	80	—	unknown	22:05–02:30 (good, 4.42 h)	87.1° 22:20	6.7	86%	82.3°
2030-08-17 Sat	85	—	unknown	22:05–03:20 (good, 5.25 h)	87.1° 22:15	6.76	78%	88.8°
2030-08-18 Sun	100	—	unknown	22:05–03:45 (good, 5.67 h)	87.1° 22:10	6.82	70%	95.2°
2030-08-19 Mon	100	—	unknown	22:00–03:50 (good, 5.83 h)	87.1° 22:05	6.87	61%	101.3°
2030-08-20 Tue	100	—	unknown	22:00–03:50 (good, 5.83 h)	87.1° 22:00	6.93	51%	106.9°
2030-08-21 Wed	100	—	unknown	21:55–03:50 (good, 5.92 h)	87.1° 22:00	6.99	42%	111.9°
2030-08-22 Thu	100	—	unknown	21:55–03:50 (good, 5.92 h)	87.1° 21:55	7.05	33%	116.0°
2030-08-23 Fri	100	—	unknown	21:55–03:45 (good, 5.83 h)	87.1° 21:50	7.1	24%	119.1°
2030-08-24 Sat	100	—	unknown	21:50–03:45 (good, 5.92 h)	87.1° 21:45	7.16	16%	120.9°
2030-08-25 Sun	100	—	unknown	21:50–03:40 (good, 5.83 h)	87.1° 21:45	7.22	10%	121.1°
2030-08-26 Mon	100	—	unknown	21:45–03:40 (good, 5.92 h)	87.1° 21:40	7.27	5%	119.7°
2030-08-27 Tue	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:35	7.33	1%	116.8°
2030-08-28 Wed	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:30	7.39	0%	112.3°
2030-08-29 Thu	100	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:25	7.44	1%	106.7°
2030-08-30 Fri	100	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:25	7.5	5%	100.2°
2030-08-31 Sat	100	—	unknown	21:35–03:20 (good, 5.75 h)	87.1° 21:20	7.56	11%	93.1°
2030-09-01 Sun	100	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.61	18%	85.9°
2030-09-02 Mon	100	—	unknown	21:35–03:10 (good, 5.58 h)	87.1° 21:10	7.67	28%	78.8°
2030-09-03 Tue	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.72	39%	72.1°
2030-09-04 Wed	100	—	unknown	21:30–03:05 (good, 5.58 h)	87.1° 21:05	7.78	50%	66.4°
2030-09-05 Thu	93	—	unknown	21:25–03:00 (good, 5.58 h)	87.1° 21:00	7.83	62%	62.0°
2030-09-06 Fri	84	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 20:55	7.89	72%	59.4°
2030-09-07 Sat	63	—	unknown	21:25–01:40 (good, 4.25 h)	87.1° 20:50	7.94	82%	58.7°
2030-09-08 Sun	53	—	unknown	21:20–21:50 (good, 0.5 h)	87.1° 20:50	8.0	90%	60.1°
2030-09-09 Mon	49	—	unknown	21:20–21:25 (good, 0.08 h)	87.1° 20:45	8.05	95%	63.4°
2030-09-10 Tue	51	—	unknown	21:15–22:00 (good, 0.75 h)	87.1° 20:40	8.11	99%	68.1°
2030-09-11 Wed	55	—	unknown	21:15–23:10 (good, 1.92 h)	87.1° 20:35	8.16	100%	73.8°
2030-09-12 Thu	63	—	unknown	21:15–23:50 (good, 2.58 h)	87.1° 20:30	8.21	99%	80.0°
2030-09-13 Fri	74	—	unknown	21:10–00:35 (good, 3.42 h)	87.1° 20:30	8.27	95%	86.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-08-15&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.