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: 06-16 (100), 06-17 (100), 06-18 (100), 06-19 (100), 06-20 (100) — by astronomy; check the weather when the night is within four days.

2037-06-16astronomy score per night — click a bar for that night2037-07-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-06-16 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.44	13%	115.2°
2037-06-17 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:15	4.43	21%	110.4°
2037-06-18 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	32%	104.5°
2037-06-19 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:05	4.42	43%	97.8°
2037-06-20 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	54%	90.8°
2037-06-21 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	65%	83.8°
2037-06-22 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.43	76%	77.2°
2037-06-23 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	85%	71.2°
2037-06-24 Wed	68	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	92%	66.2°
2037-06-25 Thu	58	—	unknown	00:55–03:40 (good, 2.75 h)	87.1° 01:40	4.45	97%	62.6°
2037-06-26 Fri	52	—	unknown	02:35–03:40 (good, 1.08 h)	87.1° 01:40	4.46	99%	60.5°
2037-06-27 Sat	51	—	unknown	23:15–23:55 (good, 0.67 h)	87.1° 01:35	4.47	100%	60.2°
2037-06-28 Sun	57	—	unknown	23:10–01:20 (good, 2.17 h)	87.1° 01:30	4.49	98%	61.4°
2037-06-29 Mon	65	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:25	4.51	95%	64.1°
2037-06-30 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.52	89%	68.0°
2037-07-01 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.55	83%	72.7°
2037-07-02 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.57	75%	78.0°
2037-07-03 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.59	66%	83.6°
2037-07-04 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.62	57%	89.5°
2037-07-05 Sun	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.65	47%	95.4°
2037-07-06 Mon	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.68	38%	101.2°
2037-07-07 Tue	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:55	4.71	28%	106.8°
2037-07-08 Wed	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.74	20%	111.8°
2037-07-09 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:45	4.78	12%	115.9°
2037-07-10 Fri	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:45	4.81	6%	118.7°
2037-07-11 Sat	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:40	4.85	2%	119.9°
2037-07-12 Sun	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.1° 00:35	4.89	0%	119.2°
2037-07-13 Mon	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.1° 00:30	4.93	1%	116.4°
2037-07-14 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	4.97	5%	112.0°
2037-07-15 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	5.01	11%	106.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-06-16&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.