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 V1057 Cyg: 08-20 (100), 08-21 (100), 08-22 (100), 08-23 (100), 08-24 (100) — by astronomy; check the weather when the night is within four days.

2036-08-20astronomy score per night — click a bar for that night2036-09-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-08-20 Wed	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.3° 00:20	6.96	1%	119.9°
2036-08-21 Thu	100	—	unknown	21:55–04:55 (good, 7.0 h)	87.3° 00:20	7.02	0%	120.9°
2036-08-22 Fri	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:15	7.08	2%	119.6°
2036-08-23 Sat	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:10	7.13	7%	116.2°
2036-08-24 Sun	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:05	7.19	14%	111.2°
2036-08-25 Mon	100	—	unknown	21:50–05:05 (good, 7.25 h)	87.3° 00:00	7.25	23%	105.2°
2036-08-26 Tue	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 00:00	7.31	33%	98.7°
2036-08-27 Wed	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 23:55	7.36	43%	92.1°
2036-08-28 Thu	100	—	unknown	21:40–05:05 (good, 7.42 h)	87.3° 23:50	7.42	53%	85.7°
2036-08-29 Fri	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.3° 23:45	7.48	63%	79.5°
2036-08-30 Sat	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.3° 23:45	7.53	72%	73.8°
2036-08-31 Sun	99	—	unknown	21:35–05:10 (good, 7.58 h)	87.3° 23:40	7.59	80%	68.7°
2036-09-01 Mon	92	—	unknown	21:35–05:15 (good, 7.67 h)	87.3° 23:35	7.64	87%	64.5°
2036-09-02 Tue	86	—	unknown	23:55–05:15 (good, 5.33 h)	87.3° 23:30	7.7	93%	61.4°
2036-09-03 Wed	60	—	unknown	21:30–21:35 (good, 0.08 h)	87.3° 23:25	7.75	97%	59.6°
2036-09-04 Thu	61	—	unknown	21:30–21:40 (good, 0.17 h)	87.3° 23:25	7.81	99%	59.1°
2036-09-05 Fri	63	—	unknown	21:25–22:10 (good, 0.75 h)	87.3° 23:20	7.86	100%	60.1°
2036-09-06 Sat	67	—	unknown	21:25–22:55 (good, 1.5 h)	87.3° 23:15	7.92	99%	62.6°
2036-09-07 Sun	72	—	unknown	21:20–00:05 (good, 2.75 h)	87.3° 23:10	7.97	96%	66.3°
2036-09-08 Mon	100	—	unknown	21:20–02:00 (good, 4.67 h)	87.3° 23:05	8.03	91%	71.1°
2036-09-09 Tue	100	—	unknown	21:20–03:00 (good, 5.67 h)	87.3° 23:05	8.08	84%	76.8°
2036-09-10 Wed	100	—	unknown	21:15–04:00 (good, 6.75 h)	87.3° 23:00	8.14	76%	83.0°
2036-09-11 Thu	100	—	unknown	21:15–04:45 (good, 7.5 h)	87.3° 22:55	8.19	66%	89.7°
2036-09-12 Fri	100	—	unknown	21:10–04:50 (good, 7.67 h)	87.3° 22:50	8.24	56%	96.5°
2036-09-13 Sat	100	—	unknown	21:10–04:55 (good, 7.75 h)	87.3° 22:50	8.3	44%	103.2°
2036-09-14 Sun	100	—	unknown	21:10–04:55 (good, 7.75 h)	87.3° 22:45	8.35	34%	109.5°
2036-09-15 Mon	100	—	unknown	21:05–04:55 (good, 7.83 h)	87.3° 22:40	8.4	23%	114.8°
2036-09-16 Tue	100	—	unknown	21:05–04:55 (good, 7.83 h)	87.3° 22:35	8.45	14%	118.7°
2036-09-17 Wed	100	—	unknown	21:05–04:50 (good, 7.75 h)	87.3° 22:30	8.51	7%	120.7°
2036-09-18 Thu	100	—	unknown	21:00–04:50 (good, 7.83 h)	87.3° 22:30	8.56	2%	120.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-08-20&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.