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: 08-03 (100), 08-04 (100), 08-05 (100), 08-06 (100), 08-07 (100) — by astronomy; check the weather when the night is within four days.

2045-08-03astronomy score per night — click a bar for that night2045-09-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-08-03 Thu	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:10	5.98	70%	87.4°
2045-08-04 Fri	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.1° 23:05	6.04	61%	92.7°
2045-08-05 Sat	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 23:00	6.09	51%	98.1°
2045-08-06 Sun	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.15	40%	103.2°
2045-08-07 Mon	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.1° 22:55	6.21	30%	107.8°
2045-08-08 Tue	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.1° 22:50	6.26	20%	111.7°
2045-08-09 Wed	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:45	6.32	11%	114.3°
2045-08-10 Thu	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.1° 22:40	6.38	5%	115.4°
2045-08-11 Fri	100	—	unknown	22:15–04:35 (good, 6.33 h)	87.1° 22:35	6.44	1%	114.5°
2045-08-12 Sat	100	—	unknown	22:15–04:30 (good, 6.25 h)	87.1° 22:35	6.49	0%	111.9°
2045-08-13 Sun	100	—	unknown	22:10–04:30 (good, 6.33 h)	87.1° 22:30	6.55	2%	107.8°
2045-08-14 Mon	100	—	unknown	22:10–04:25 (good, 6.25 h)	87.1° 22:25	6.61	7%	102.5°
2045-08-15 Tue	100	—	unknown	22:10–04:20 (good, 6.17 h)	87.1° 22:20	6.67	14%	96.7°
2045-08-16 Wed	100	—	unknown	22:05–04:15 (good, 6.17 h)	87.1° 22:15	6.72	24%	90.7°
2045-08-17 Thu	100	—	unknown	22:05–04:15 (good, 6.17 h)	87.1° 22:15	6.78	34%	84.8°
2045-08-18 Fri	100	—	unknown	22:00–04:10 (good, 6.17 h)	87.1° 22:10	6.84	44%	79.4°
2045-08-19 Sat	100	—	unknown	22:00–04:05 (good, 6.08 h)	87.1° 22:05	6.9	55%	74.6°
2045-08-20 Sun	100	—	unknown	22:00–04:00 (good, 6.0 h)	87.1° 22:00	6.95	64%	70.6°
2045-08-21 Mon	96	—	unknown	21:55–03:55 (good, 6.0 h)	87.1° 22:00	7.01	74%	67.5°
2045-08-22 Tue	88	—	unknown	21:55–03:55 (good, 6.0 h)	87.1° 21:55	7.07	82%	65.5°
2045-08-23 Wed	81	—	unknown	21:55–03:50 (good, 5.92 h)	87.1° 21:50	7.13	88%	64.7°
2045-08-24 Thu	64	—	unknown	21:50–01:25 (good, 3.58 h)	87.1° 21:45	7.18	94%	65.0°
2045-08-25 Fri	61	—	unknown	21:50–00:25 (good, 2.58 h)	87.1° 21:40	7.24	98%	66.4°
2045-08-26 Sat	60	—	unknown	21:45–23:40 (good, 1.92 h)	87.1° 21:40	7.3	100%	68.9°
2045-08-27 Sun	62	—	unknown	21:45–00:15 (good, 2.5 h)	87.1° 21:35	7.35	100%	72.3°
2045-08-28 Mon	68	—	unknown	21:45–00:35 (good, 2.83 h)	87.1° 21:30	7.41	98%	76.4°
2045-08-29 Tue	75	—	unknown	21:40–01:05 (good, 3.42 h)	87.1° 21:25	7.47	95%	81.1°
2045-08-30 Wed	80	—	unknown	21:40–01:45 (good, 4.08 h)	87.1° 21:20	7.52	90%	86.1°
2045-08-31 Thu	84	—	unknown	21:35–02:25 (good, 4.83 h)	87.1° 21:20	7.58	83%	91.4°
2045-09-01 Fri	100	—	unknown	21:35–02:50 (good, 5.25 h)	87.1° 21:15	7.63	75%	96.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-08-03&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.