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: 07-09 (100), 07-10 (100), 07-11 (100), 07-19 (100), 07-20 (100) — by astronomy; check the weather when the night is within four days.

2030-07-09astronomy score per night — click a bar for that night2030-08-07

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-07-09 Tue	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.77	66%	82.8°
2030-07-10 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.8	77%	75.8°
2030-07-11 Thu	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.84	86%	69.3°
2030-07-12 Fri	71	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.88	93%	64.0°
2030-07-13 Sat	58	—	unknown	01:40–03:55 (good, 2.25 h)	87.1° 00:30	4.92	98%	60.4°
2030-07-14 Sun	51	—	unknown	23:00–04:00 (marginal, 5.0 h)	87.1° 00:30	4.96	100%	58.9°
2030-07-15 Mon	53	—	unknown	23:00–23:35 (good, 0.58 h)	87.1° 00:25	5.0	99%	59.7°
2030-07-16 Tue	60	—	unknown	23:00–00:50 (good, 1.83 h)	87.1° 00:20	5.04	95%	62.4°
2030-07-17 Wed	72	—	unknown	22:55–03:00 (good, 4.08 h)	87.1° 00:15	5.09	89%	66.8°
2030-07-18 Thu	79	—	unknown	22:55–03:55 (good, 5.0 h)	87.1° 00:10	5.13	82%	72.2°
2030-07-19 Fri	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.18	73%	78.2°
2030-07-20 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.23	64%	84.5°
2030-07-21 Sun	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 00:00	5.27	54%	90.9°
2030-07-22 Mon	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.32	44%	97.1°
2030-07-23 Tue	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:50	5.37	35%	103.0°
2030-07-24 Wed	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 23:50	5.42	26%	108.4°
2030-07-25 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:45	5.48	18%	113.1°
2030-07-26 Fri	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.53	12%	117.0°
2030-07-27 Sat	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.1° 23:35	5.58	6%	119.7°
2030-07-28 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.63	2%	121.0°
2030-07-29 Mon	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:30	5.69	0%	120.8°
2030-07-30 Tue	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:25	5.74	0%	118.9°
2030-07-31 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.79	2%	115.5°
2030-08-01 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.85	7%	110.8°
2030-08-02 Fri	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.9	13%	105.0°
2030-08-03 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.96	21%	98.5°
2030-08-04 Sun	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	6.02	31%	91.6°
2030-08-05 Mon	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:00	6.07	41%	84.4°
2030-08-06 Tue	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.13	53%	77.4°
2030-08-07 Wed	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.19	64%	71.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-07-09&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.