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: 09-01 (100), 09-02 (100), 09-03 (100), 09-04 (100), 09-05 (100) — by astronomy; check the weather when the night is within four days.

2034-08-30astronomy score per night — click a bar for that night2034-09-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-08-30 Wed	64	—	unknown	21:40–22:30 (good, 0.83 h)	87.3° 23:45	7.5	98%	58.5°
2034-08-31 Thu	71	—	unknown	21:35–00:00 (good, 2.42 h)	87.3° 23:40	7.56	94%	62.9°
2034-09-01 Fri	100	—	unknown	21:35–02:30 (good, 4.92 h)	87.3° 23:35	7.61	87%	69.0°
2034-09-02 Sat	100	—	unknown	21:35–03:45 (good, 6.17 h)	87.3° 23:35	7.67	78%	76.1°
2034-09-03 Sun	100	—	unknown	21:30–05:05 (good, 7.58 h)	87.3° 23:30	7.73	68%	83.9°
2034-09-04 Mon	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.3° 23:25	7.78	56%	91.9°
2034-09-05 Tue	100	—	unknown	21:25–05:15 (good, 7.83 h)	87.3° 23:20	7.84	45%	99.7°
2034-09-06 Wed	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.3° 23:15	7.89	34%	107.1°
2034-09-07 Thu	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.3° 23:15	7.95	24%	113.6°
2034-09-08 Fri	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.3° 23:10	8.0	15%	118.8°
2034-09-09 Sat	100	—	unknown	21:20–05:25 (good, 8.08 h)	87.3° 23:05	8.05	8%	122.4°
2034-09-10 Sun	100	—	unknown	21:15–05:20 (good, 8.08 h)	87.3° 23:00	8.11	3%	124.1°
2034-09-11 Mon	100	—	unknown	21:15–05:15 (good, 8.0 h)	87.3° 23:00	8.16	1%	123.8°
2034-09-12 Tue	100	—	unknown	21:15–05:15 (good, 8.0 h)	87.3° 22:55	8.22	0%	121.6°
2034-09-13 Wed	100	—	unknown	21:10–05:10 (good, 8.0 h)	87.3° 22:50	8.27	2%	117.8°
2034-09-14 Thu	100	—	unknown	21:10–05:05 (good, 7.92 h)	87.3° 22:45	8.32	5%	112.9°
2034-09-15 Fri	100	—	unknown	21:10–05:00 (good, 7.83 h)	87.3° 22:40	8.38	10%	107.2°
2034-09-16 Sat	100	—	unknown	21:05–05:00 (good, 7.92 h)	87.3° 22:40	8.43	17%	100.9°
2034-09-17 Sun	100	—	unknown	21:05–04:55 (good, 7.83 h)	87.3° 22:35	8.48	24%	94.4°
2034-09-18 Mon	100	—	unknown	21:00–04:50 (good, 7.83 h)	87.3° 22:30	8.53	33%	87.7°
2034-09-19 Tue	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.3° 22:25	8.58	42%	81.1°
2034-09-20 Wed	100	—	unknown	21:00–04:40 (good, 7.67 h)	87.3° 22:20	8.64	51%	74.8°
2034-09-21 Thu	100	—	unknown	20:55–04:40 (good, 7.75 h)	87.3° 22:20	8.69	61%	68.8°
2034-09-22 Fri	94	—	unknown	20:55–04:35 (good, 7.67 h)	87.3° 22:15	8.74	71%	63.5°
2034-09-23 Sat	87	—	unknown	20:50–04:30 (good, 7.67 h)	87.3° 22:10	8.79	79%	59.3°
2034-09-24 Sun	77	—	unknown	00:20–02:00 (good, 1.67 h)	87.3° 22:05	8.84	87%	56.5°
2034-09-25 Mon	57	—	unknown	20:50–04:55 (marginal, 8.08 h)	87.3° 22:00	8.89	94%	55.8°
2034-09-26 Tue	58	—	unknown	20:45–04:40 (marginal, 7.92 h)	87.3° 22:00	8.94	98%	57.2°
2034-09-27 Wed	62	—	unknown	20:45–21:05 (good, 0.33 h)	87.3° 21:55	8.99	100%	60.9°
2034-09-28 Thu	67	—	unknown	20:45–22:25 (good, 1.67 h)	87.3° 21:50	9.04	99%	66.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-08-30&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.