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: 08-12 (100), 08-13 (100), 08-14 (100), 08-15 (100), 08-16 (100) — by astronomy; check the weather when the night is within four days.

2034-08-12astronomy score per night — click a bar for that night2034-09-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-08-12 Sat	100	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:35	6.47	2%	120.4°
2034-08-13 Sun	100	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:30	6.53	0%	116.3°
2034-08-14 Mon	100	—	unknown	22:10–04:25 (good, 6.25 h)	87.1° 22:25	6.59	1%	110.9°
2034-08-15 Tue	100	—	unknown	22:10–04:20 (good, 6.17 h)	87.1° 22:20	6.65	4%	104.7°
2034-08-16 Wed	100	—	unknown	22:05–04:15 (good, 6.17 h)	87.1° 22:20	6.7	8%	98.1°
2034-08-17 Thu	100	—	unknown	22:05–04:15 (good, 6.17 h)	87.1° 22:15	6.76	15%	91.3°
2034-08-18 Fri	100	—	unknown	22:05–04:10 (good, 6.08 h)	87.1° 22:10	6.82	22%	84.6°
2034-08-19 Sat	100	—	unknown	22:00–04:05 (good, 6.08 h)	87.1° 22:05	6.88	31%	78.2°
2034-08-20 Sun	100	—	unknown	22:00–04:00 (good, 6.0 h)	87.1° 22:00	6.93	40%	72.3°
2034-08-21 Mon	100	—	unknown	21:55–04:00 (good, 6.08 h)	87.1° 22:00	6.99	49%	67.0°
2034-08-22 Tue	98	—	unknown	21:55–03:55 (good, 6.0 h)	87.1° 21:55	7.05	58%	62.5°
2034-08-23 Wed	93	—	unknown	21:55–03:50 (good, 5.92 h)	87.1° 21:50	7.11	68%	59.1°
2034-08-24 Thu	87	—	unknown	21:50–03:45 (good, 5.92 h)	87.1° 21:45	7.16	77%	57.2°
2034-08-25 Fri	79	—	unknown	21:50–02:55 (good, 5.08 h)	87.1° 21:45	7.22	84%	56.9°
2034-08-26 Sat	56	—	unknown	21:45–04:10 (marginal, 6.42 h)	87.1° 21:40	7.28	91%	58.4°
2034-08-27 Sun	53	—	unknown	21:10–04:00 (marginal, 6.83 h)	87.1° 21:35	7.33	96%	61.7°
2034-08-28 Mon	56	—	unknown	21:45–22:35 (good, 0.83 h)	87.1° 21:30	7.39	99%	66.6°
2034-08-29 Tue	62	—	unknown	21:40–00:10 (good, 2.5 h)	87.1° 21:25	7.45	100%	72.7°
2034-08-30 Wed	72	—	unknown	21:40–00:55 (good, 3.25 h)	87.1° 21:25	7.5	98%	79.9°
2034-08-31 Thu	80	—	unknown	21:35–01:45 (good, 4.17 h)	87.1° 21:20	7.56	94%	87.5°
2034-09-01 Fri	100	—	unknown	21:35–02:40 (good, 5.08 h)	87.1° 21:15	7.61	87%	95.4°
2034-09-02 Sat	100	—	unknown	21:35–02:50 (good, 5.25 h)	87.1° 21:10	7.67	78%	103.0°
2034-09-03 Sun	100	—	unknown	21:30–02:55 (good, 5.42 h)	87.1° 21:05	7.73	68%	110.0°
2034-09-04 Mon	100	—	unknown	21:30–02:55 (good, 5.42 h)	87.1° 21:05	7.78	56%	115.9°
2034-09-05 Tue	100	—	unknown	21:25–02:55 (good, 5.5 h)	87.1° 21:00	7.84	45%	120.3°
2034-09-06 Wed	100	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:55	7.89	34%	122.8°
2034-09-07 Thu	100	—	unknown	21:25–02:50 (good, 5.42 h)	87.1° 20:50	7.95	24%	123.1°
2034-09-08 Fri	100	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:50	8.0	15%	121.4°
2034-09-09 Sat	100	—	unknown	21:20–02:45 (good, 5.42 h)	87.1° 20:45	8.05	8%	117.8°
2034-09-10 Sun	100	—	unknown	21:15–02:40 (good, 5.42 h)	87.1° 20:40	8.11	3%	112.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-08-12&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.