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: 04-29 (100), 04-30 (100), 05-01 (100), 05-02 (100), 05-03 (100) — by astronomy; check the weather when the night is within four days.

2044-04-29astronomy score per night — click a bar for that night2044-05-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-04-29 Fri	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.44	6%	107.8°
2044-04-30 Sat	100	—	unknown	23:30–04:30 (good, 5.0 h)	87.1° 05:20	6.38	14%	111.2°
2044-05-01 Sun	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:15	6.33	23%	113.3°
2044-05-02 Mon	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:15	6.27	33%	113.8°
2044-05-03 Tue	100	—	unknown	23:20–04:25 (good, 5.08 h)	87.1° 05:10	6.21	44%	112.7°
2044-05-04 Wed	100	—	unknown	23:20–04:25 (good, 5.08 h)	87.1° 05:05	6.15	56%	110.3°
2044-05-05 Thu	100	—	unknown	23:20–04:25 (good, 5.08 h)	87.1° 05:00	6.1	66%	106.8°
2044-05-06 Fri	100	—	unknown	23:25–04:20 (good, 4.92 h)	87.1° 04:55	6.04	76%	102.5°
2044-05-07 Sat	100	—	unknown	23:25–04:20 (good, 4.92 h)	87.1° 04:55	5.98	84%	97.7°
2044-05-08 Sun	83	—	unknown	23:40–04:20 (good, 4.67 h)	87.1° 04:50	5.93	91%	92.6°
2044-05-09 Mon	79	—	unknown	00:05–04:15 (good, 4.17 h)	87.1° 04:45	5.87	96%	87.6°
2044-05-10 Tue	75	—	unknown	00:25–04:15 (good, 3.83 h)	87.1° 04:40	5.81	99%	82.7°
2044-05-11 Wed	72	—	unknown	00:30–04:15 (good, 3.75 h)	87.1° 04:40	5.76	100%	78.1°
2044-05-12 Thu	68	—	unknown	00:15–04:10 (good, 3.92 h)	87.1° 04:35	5.7	99%	74.1°
2044-05-13 Fri	68	—	unknown	23:30–04:10 (good, 4.67 h)	87.1° 04:30	5.65	96%	70.7°
2044-05-14 Sat	83	—	unknown	22:30–04:10 (good, 5.67 h)	87.1° 04:25	5.6	92%	68.2°
2044-05-15 Sun	90	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:20	5.54	86%	66.6°
2044-05-16 Mon	95	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:20	5.49	79%	66.1°
2044-05-17 Tue	99	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.44	71%	66.6°
2044-05-18 Wed	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:10	5.39	62%	68.3°
2044-05-19 Thu	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.34	52%	70.9°
2044-05-20 Fri	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.29	42%	74.5°
2044-05-21 Sat	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 04:00	5.24	32%	78.9°
2044-05-22 Sun	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.19	23%	83.9°
2044-05-23 Mon	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.14	14%	89.5°
2044-05-24 Tue	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:45	5.1	7%	95.2°
2044-05-25 Wed	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:45	5.05	2%	100.8°
2044-05-26 Thu	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.01	0%	106.0°
2044-05-27 Fri	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.97	1%	110.1°
2044-05-28 Sat	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.92	5%	112.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-04-29&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.