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: 07-14 (100), 07-15 (100), 07-16 (100), 07-17 (100), 07-18 (100) — by astronomy; check the weather when the night is within four days.

2040-07-14astronomy score per night — click a bar for that night2040-08-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2040-07-14 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:25	4.98	26%	95.5°
2040-07-15 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:20	5.02	35%	90.3°
2040-07-16 Mon	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 00:20	5.07	45%	84.9°
2040-07-17 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:15	5.11	56%	79.6°
2040-07-18 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:10	5.16	66%	74.7°
2040-07-19 Thu	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.1° 00:05	5.21	77%	70.3°
2040-07-20 Fri	99	—	unknown	22:55–04:10 (good, 5.25 h)	87.1° 00:00	5.25	86%	67.1°
2040-07-21 Sat	93	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 00:00	5.3	93%	65.2°
2040-07-22 Sun	66	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.35	98%	65.1°
2040-07-23 Mon	66	—	unknown	22:50–03:40 (good, 4.83 h)	87.1° 23:50	5.4	100%	66.9°
2040-07-24 Tue	71	—	unknown	22:45–03:10 (good, 4.42 h)	87.1° 23:45	5.45	99%	70.3°
2040-07-25 Wed	76	—	unknown	22:45–03:30 (good, 4.75 h)	87.1° 23:45	5.5	95%	75.0°
2040-07-26 Thu	100	—	unknown	22:45–04:05 (good, 5.33 h)	87.1° 23:40	5.56	88%	80.5°
2040-07-27 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.61	80%	86.3°
2040-07-28 Sat	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:30	5.66	70%	92.2°
2040-07-29 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:25	5.72	60%	97.7°
2040-07-30 Mon	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:25	5.77	49%	102.7°
2040-07-31 Tue	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.83	39%	107.0°
2040-08-01 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:15	5.88	30%	110.6°
2040-08-02 Thu	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.94	22%	113.1°
2040-08-03 Fri	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	5.99	14%	114.6°
2040-08-04 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	6.05	8%	115.0°
2040-08-05 Sun	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 23:00	6.1	4%	114.2°
2040-08-06 Mon	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.16	1%	112.4°
2040-08-07 Tue	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:50	6.22	0%	109.6°
2040-08-08 Wed	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:50	6.28	1%	106.0°
2040-08-09 Thu	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.33	4%	101.7°
2040-08-10 Fri	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.1° 22:40	6.39	8%	96.9°
2040-08-11 Sat	100	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:35	6.45	14%	91.7°
2040-08-12 Sun	100	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:30	6.5	22%	86.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2040-07-14&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.