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: 04-25 (100), 04-26 (100), 04-27 (100), 04-28 (100), 04-29 (100) — by astronomy; check the weather when the night is within four days.

2047-04-25astronomy score per night — click a bar for that night2047-05-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-04-25 Thu	100	—	unknown	23:50–04:45 (good, 4.92 h)	87.1° 05:45	6.72	1%	98.9°
2047-04-26 Fri	100	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:40	6.66	3%	104.1°
2047-04-27 Sat	100	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.6	7%	108.8°
2047-04-28 Sun	100	—	unknown	23:40–04:35 (good, 4.92 h)	87.1° 05:30	6.54	12%	112.9°
2047-04-29 Mon	100	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.48	19%	116.0°
2047-04-30 Tue	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.43	28%	117.9°
2047-05-01 Wed	100	—	unknown	23:30–04:30 (good, 5.0 h)	87.1° 05:20	6.37	37%	118.4°
2047-05-02 Thu	100	—	unknown	23:30–04:30 (good, 5.0 h)	87.1° 05:15	6.31	48%	117.4°
2047-05-03 Fri	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:10	6.25	58%	114.7°
2047-05-04 Sat	100	—	unknown	23:25–04:25 (good, 5.0 h)	87.1° 05:10	6.19	69%	110.6°
2047-05-05 Sun	100	—	unknown	23:30–04:25 (good, 4.92 h)	87.1° 05:05	6.14	79%	105.2°
2047-05-06 Mon	100	—	unknown	23:30–04:20 (good, 4.83 h)	87.1° 05:00	6.08	88%	98.8°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-04-25&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.