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: 08-14 (100), 08-15 (100), 08-16 (100), 08-17 (100), 08-18 (100) — by astronomy; check the weather when the night is within four days.

2034-08-14astronomy score per night — click a bar for that night2034-09-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-08-14 Mon	100	—	unknown	22:10–04:45 (good, 6.58 h)	87.3° 00:50	6.59	1%	124.2°
2034-08-15 Tue	100	—	unknown	22:10–04:50 (good, 6.67 h)	87.3° 00:45	6.65	4%	123.3°
2034-08-16 Wed	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.3° 00:40	6.7	8%	120.5°
2034-08-17 Thu	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.3° 00:35	6.76	15%	116.3°
2034-08-18 Fri	100	—	unknown	22:05–04:50 (good, 6.75 h)	87.3° 00:30	6.82	22%	111.0°
2034-08-19 Sat	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.3° 00:30	6.88	31%	105.1°
2034-08-20 Sun	100	—	unknown	22:00–04:55 (good, 6.92 h)	87.3° 00:25	6.93	40%	98.8°
2034-08-21 Mon	100	—	unknown	21:55–04:55 (good, 7.0 h)	87.3° 00:20	6.99	49%	92.2°
2034-08-22 Tue	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:15	7.05	58%	85.5°
2034-08-23 Wed	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.3° 00:10	7.11	68%	78.9°
2034-08-24 Thu	100	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:10	7.16	77%	72.6°
2034-08-25 Fri	98	—	unknown	21:50–05:00 (good, 7.17 h)	87.3° 00:05	7.22	84%	66.7°
2034-08-26 Sat	91	—	unknown	21:45–05:05 (good, 7.33 h)	87.3° 00:00	7.28	91%	61.7°
2034-08-27 Sun	60	—	unknown	02:40–03:20 (good, 0.67 h)	87.3° 23:55	7.33	96%	58.0°
2034-08-28 Mon	57	—	unknown	21:45–05:05 (marginal, 7.33 h)	87.3° 23:55	7.39	99%	56.0°
2034-08-29 Tue	60	—	unknown	21:05–05:10 (marginal, 8.08 h)	87.3° 23:50	7.45	100%	56.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-08-14&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.