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: 08-21 (100), 08-22 (100), 08-23 (100), 08-24 (100), 08-25 (100) — by astronomy; check the weather when the night is within four days.

2036-08-21astronomy score per night — click a bar for that night2036-09-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-08-21 Thu	100	—	unknown	21:55–03:55 (good, 6.0 h)	87.1° 21:55	7.02	0%	107.6°
2036-08-22 Fri	100	—	unknown	21:55–03:50 (good, 5.92 h)	87.1° 21:55	7.08	2%	100.5°
2036-08-23 Sat	100	—	unknown	21:50–03:50 (good, 6.0 h)	87.1° 21:50	7.13	7%	92.9°
2036-08-24 Sun	100	—	unknown	21:50–03:45 (good, 5.92 h)	87.1° 21:45	7.19	14%	85.4°
2036-08-25 Mon	100	—	unknown	21:50–03:40 (good, 5.83 h)	87.1° 21:40	7.25	23%	78.4°
2036-08-26 Tue	100	—	unknown	21:45–03:35 (good, 5.83 h)	87.1° 21:35	7.31	33%	72.1°
2036-08-27 Wed	100	—	unknown	21:45–03:30 (good, 5.75 h)	87.1° 21:35	7.36	43%	66.8°
2036-08-28 Thu	98	—	unknown	21:40–03:30 (good, 5.83 h)	87.1° 21:30	7.42	53%	62.7°
2036-08-29 Fri	93	—	unknown	21:40–03:25 (good, 5.75 h)	87.1° 21:25	7.48	63%	60.0°
2036-08-30 Sat	87	—	unknown	21:40–03:20 (good, 5.67 h)	87.1° 21:20	7.53	72%	58.7°
2036-08-31 Sun	82	—	unknown	21:35–03:15 (good, 5.67 h)	87.1° 21:15	7.59	80%	59.0°
2036-09-01 Mon	62	—	unknown	21:35–01:15 (good, 3.67 h)	87.1° 21:15	7.64	87%	60.8°
2036-09-02 Tue	58	—	unknown	21:30–00:10 (good, 2.67 h)	87.1° 21:10	7.7	93%	63.9°
2036-09-03 Wed	58	—	unknown	21:30–23:50 (good, 2.33 h)	87.1° 21:05	7.75	97%	68.0°
2036-09-04 Thu	60	—	unknown	21:30–00:00 (good, 2.5 h)	87.1° 21:00	7.81	99%	73.0°
2036-09-05 Fri	67	—	unknown	21:25–00:25 (good, 3.0 h)	87.1° 21:00	7.86	100%	78.7°
2036-09-06 Sat	75	—	unknown	21:25–00:55 (good, 3.5 h)	87.1° 20:55	7.92	99%	84.8°
2036-09-07 Sun	81	—	unknown	21:20–01:35 (good, 4.25 h)	87.1° 20:50	7.97	96%	91.1°
2036-09-08 Mon	100	—	unknown	21:20–02:15 (good, 4.92 h)	87.1° 20:45	8.03	91%	97.5°
2036-09-09 Tue	100	—	unknown	21:20–02:20 (good, 5.0 h)	87.1° 20:40	8.08	84%	103.7°
2036-09-10 Wed	100	—	unknown	21:15–02:20 (good, 5.08 h)	87.1° 20:40	8.14	76%	109.5°
2036-09-11 Thu	100	—	unknown	21:15–02:20 (good, 5.08 h)	87.1° 20:35	8.19	66%	114.5°
2036-09-12 Fri	100	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:30	8.24	56%	118.4°
2036-09-13 Sat	100	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:25	8.3	44%	120.8°
2036-09-14 Sun	100	—	unknown	21:10–02:20 (good, 5.17 h)	87.1° 20:20	8.35	34%	121.2°
2036-09-15 Mon	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:20	8.4	23%	119.5°
2036-09-16 Tue	100	—	unknown	21:05–02:15 (good, 5.17 h)	87.1° 20:15	8.45	14%	115.8°
2036-09-17 Wed	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.51	7%	110.4°
2036-09-18 Thu	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.56	2%	103.7°
2036-09-19 Fri	100	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:00	8.61	0%	96.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-08-21&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.