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: 05-15 (100), 05-16 (100), 05-17 (100), 05-18 (100), 05-19 (100) — by astronomy; check the weather when the night is within four days.

2047-05-07astronomy score per night — click a bar for that night2047-06-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-05-07 Tue	82	—	unknown	23:50–04:20 (good, 4.5 h)	87.1° 04:55	6.02	95%	91.7°
2047-05-08 Wed	76	—	unknown	00:25–04:20 (good, 3.92 h)	87.1° 04:50	5.97	99%	84.5°
2047-05-09 Thu	69	—	unknown	00:45–04:15 (good, 3.5 h)	87.1° 04:50	5.91	100%	77.6°
2047-05-10 Fri	65	—	unknown	00:40–04:15 (good, 3.58 h)	87.1° 04:45	5.85	98%	71.5°
2047-05-11 Sat	74	—	unknown	23:35–04:15 (good, 4.67 h)	87.1° 04:40	5.8	93%	66.5°
2047-05-12 Sun	86	—	unknown	22:40–04:10 (good, 5.5 h)	87.1° 04:35	5.74	86%	63.2°
2047-05-13 Mon	91	—	unknown	22:40–04:10 (good, 5.5 h)	87.1° 04:35	5.69	78%	61.6°
2047-05-14 Tue	96	—	unknown	22:35–04:10 (good, 5.58 h)	87.1° 04:30	5.64	68%	61.8°
2047-05-15 Wed	100	—	unknown	22:30–04:05 (good, 5.58 h)	87.1° 04:25	5.58	58%	63.6°
2047-05-16 Thu	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:20	5.53	48%	66.7°
2047-05-17 Fri	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.48	38%	70.7°
2047-05-18 Sat	100	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.42	29%	75.5°
2047-05-19 Sun	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:10	5.37	21%	80.7°
2047-05-20 Mon	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.32	14%	86.2°
2047-05-21 Tue	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.27	8%	91.9°
2047-05-22 Wed	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.23	4%	97.4°
2047-05-23 Thu	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.18	1%	102.8°
2047-05-24 Fri	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.13	0%	107.8°
2047-05-25 Sat	100	—	unknown	22:50–03:55 (good, 5.08 h)	87.1° 03:45	5.09	1%	112.1°
2047-05-26 Sun	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.04	4%	115.5°
2047-05-27 Mon	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.0	9%	117.7°
2047-05-28 Tue	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.96	16%	118.6°
2047-05-29 Wed	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.91	24%	117.9°
2047-05-30 Thu	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:25	4.87	33%	115.7°
2047-05-31 Fri	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.84	44%	112.0°
2047-06-01 Sat	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.8	55%	107.1°
2047-06-02 Sun	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.76	66%	101.1°
2047-06-03 Mon	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.73	77%	94.5°
2047-06-04 Tue	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.7	86%	87.5°
2047-06-05 Wed	79	—	unknown	23:00–03:40 (good, 4.67 h)	87.1° 03:00	4.67	93%	80.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-05-07&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.