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: 06-19 (100), 06-20 (100), 06-21 (100), 06-22 (100), 06-23 (100) — by astronomy; check the weather when the night is within four days.

2030-06-16astronomy score per night — click a bar for that night2030-07-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-06-16 Sun	53	—	unknown	23:10–00:50 (good, 1.67 h)	87.1° 02:20	4.44	98%	59.5°
2030-06-17 Mon	59	—	unknown	23:10–02:00 (good, 2.83 h)	87.1° 02:15	4.43	93%	58.9°
2030-06-18 Tue	93	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:10	4.43	86%	60.5°
2030-06-19 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 02:05	4.42	78%	63.9°
2030-06-20 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	68%	68.6°
2030-06-21 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 02:00	4.42	58%	74.2°
2030-06-22 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:55	4.42	48%	80.2°
2030-06-23 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:50	4.43	38%	86.4°
2030-06-24 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	29%	92.6°
2030-06-25 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:45	4.44	21%	98.7°
2030-06-26 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:40	4.46	14%	104.5°
2030-06-27 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:35	4.47	8%	109.7°
2030-06-28 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.1° 01:30	4.48	4%	114.2°
2030-06-29 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.1° 01:25	4.5	1%	117.8°
2030-06-30 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:25	4.52	0%	120.2°
2030-07-01 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:20	4.54	1%	121.1°
2030-07-02 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:15	4.56	4%	120.5°
2030-07-03 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:10	4.58	9%	118.3°
2030-07-04 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.1° 01:05	4.61	16%	114.6°
2030-07-05 Fri	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:05	4.64	24%	109.7°
2030-07-06 Sat	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 01:00	4.67	34%	103.8°
2030-07-07 Sun	100	—	unknown	23:10–03:50 (good, 4.67 h)	87.1° 00:55	4.7	44%	97.2°
2030-07-08 Mon	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.1° 00:50	4.73	55%	90.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-06-16&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.