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: 07-22 (100), 07-23 (100), 07-24 (100), 07-25 (100), 07-26 (100) — by astronomy; check the weather when the night is within four days.

2039-07-22astronomy score per night — click a bar for that night2039-08-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-07-22 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.31	3%	109.2°
2039-07-23 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.1° 23:55	5.36	7%	104.7°
2039-07-24 Sun	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.1° 23:50	5.41	13%	99.5°
2039-07-25 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:45	5.47	21%	93.8°
2039-07-26 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.52	30%	87.9°
2039-07-27 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 23:40	5.57	41%	81.9°
2039-07-28 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:35	5.62	52%	76.2°
2039-07-29 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:30	5.68	64%	71.1°
2039-07-30 Sat	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 23:25	5.73	74%	67.1°
2039-07-31 Sun	96	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.78	84%	64.4°
2039-08-01 Mon	89	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 23:20	5.84	92%	63.4°
2039-08-02 Tue	64	—	unknown	22:35–04:00 (good, 5.42 h)	87.1° 23:15	5.89	97%	64.4°
2039-08-03 Wed	66	—	unknown	22:30–02:30 (good, 4.0 h)	87.1° 23:10	5.95	100%	67.0°
2039-08-04 Thu	70	—	unknown	22:30–02:20 (good, 3.83 h)	87.1° 23:05	6.01	100%	71.1°
2039-08-05 Fri	74	—	unknown	22:30–02:40 (good, 4.17 h)	87.1° 23:00	6.06	97%	76.1°
2039-08-06 Sat	80	—	unknown	22:25–03:15 (good, 4.83 h)	87.1° 23:00	6.12	92%	81.7°
2039-08-07 Sun	100	—	unknown	22:25–03:55 (good, 5.5 h)	87.1° 22:55	6.18	85%	87.6°
2039-08-08 Mon	100	—	unknown	22:20–04:20 (good, 6.0 h)	87.1° 22:50	6.23	77%	93.3°
2039-08-09 Tue	100	—	unknown	22:20–04:25 (good, 6.08 h)	87.1° 22:45	6.29	68%	98.8°
2039-08-10 Wed	100	—	unknown	22:20–04:25 (good, 6.08 h)	87.1° 22:45	6.35	58%	103.7°
2039-08-11 Thu	100	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:40	6.4	49%	108.1°
2039-08-12 Fri	100	—	unknown	22:15–04:25 (good, 6.17 h)	87.1° 22:35	6.46	40%	111.7°
2039-08-13 Sat	100	—	unknown	22:15–04:25 (good, 6.17 h)	87.1° 22:30	6.52	30%	114.4°
2039-08-14 Sun	100	—	unknown	22:10–04:25 (good, 6.25 h)	87.1° 22:25	6.58	22%	116.0°
2039-08-15 Mon	100	—	unknown	22:10–04:20 (good, 6.17 h)	87.1° 22:25	6.63	15%	116.5°
2039-08-16 Tue	100	—	unknown	22:05–04:20 (good, 6.25 h)	87.1° 22:20	6.69	9%	115.6°
2039-08-17 Wed	100	—	unknown	22:05–04:15 (good, 6.17 h)	87.1° 22:15	6.75	4%	113.6°
2039-08-18 Thu	100	—	unknown	22:05–04:10 (good, 6.08 h)	87.1° 22:10	6.81	1%	110.4°
2039-08-19 Fri	100	—	unknown	22:00–04:05 (good, 6.08 h)	87.1° 22:05	6.86	0%	106.1°
2039-08-20 Sat	100	—	unknown	22:00–04:05 (good, 6.08 h)	87.1° 22:05	6.92	1%	101.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-07-22&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.