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: 10-10 (100), 10-11 (100), 10-12 (100), 10-13 (100), 10-14 (100) — by astronomy; check the weather when the night is within four days.

2026-10-10astronomy score per night — click a bar for that night2026-11-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2026-10-10 Sat	100	98	98	20:25–03:25 (good, 7.0 h)	87.3° 21:05	9.6	0%	117.5°
2026-10-11 Sun	100	0	0	—	87.3° 21:00	9.64	2%	112.4°
2026-10-12 Mon	100	0	0	—	87.3° 20:55	9.69	6%	106.5°
2026-10-13 Tue	100	0	0	03:00–03:10 (good, 0.17 h)	87.3° 20:50	9.73	11%	100.1°
2026-10-14 Wed	100	—	unknown	20:15–03:05 (good, 6.83 h)	87.3° 20:50	9.78	17%	93.5°
2026-10-15 Thu	100	—	unknown	20:15–03:05 (good, 6.83 h)	87.3° 20:45	9.82	25%	86.9°
2026-10-16 Fri	100	—	unknown	20:15–03:00 (good, 6.75 h)	87.3° 20:40	9.86	34%	80.4°
2026-10-17 Sat	100	—	unknown	20:10–02:55 (good, 6.75 h)	87.3° 20:35	9.91	43%	74.2°
2026-10-18 Sun	95	—	unknown	20:10–02:50 (good, 6.67 h)	87.3° 20:30	9.95	52%	68.4°
2026-10-19 Mon	87	—	unknown	20:10–02:50 (good, 6.67 h)	87.3° 20:30	9.99	62%	63.5°
2026-10-20 Tue	79	—	unknown	20:10–02:45 (good, 6.58 h)	87.3° 20:25	10.03	71%	59.5°
2026-10-21 Wed	62	—	unknown	20:05–23:55 (good, 3.83 h)	87.3° 20:20	10.08	80%	56.9°
2026-10-22 Thu	56	—	unknown	20:05–03:00 (marginal, 6.92 h)	87.3° 20:15	10.12	87%	56.1°
2026-10-23 Fri	49	—	unknown	20:05–02:45 (marginal, 6.67 h)	87.3° 20:10	10.16	94%	57.3°
2026-10-24 Sat	49	—	unknown	20:00–02:30 (marginal, 6.5 h)	87.3° 20:10	10.2	98%	60.6°
2026-10-25 Sun	53	—	unknown	19:00–19:20 (good, 0.33 h)	87.3° 19:05	10.24	100%	65.6°
2026-10-26 Mon	64	—	unknown	19:00–20:50 (good, 1.83 h)	87.3° 19:00	10.28	99%	72.2°
2026-10-27 Tue	75	—	unknown	19:00–22:25 (good, 3.42 h)	87.3° 18:55	10.31	96%	79.7°
2026-10-28 Wed	82	—	unknown	18:55–23:35 (good, 4.67 h)	87.3° 18:55	10.35	90%	87.8°
2026-10-29 Thu	100	—	unknown	18:55–00:35 (good, 5.67 h)	87.3° 18:50	10.39	81%	95.9°
2026-10-30 Fri	100	—	unknown	18:55–00:45 (good, 5.83 h)	87.3° 18:45	10.43	71%	103.7°
2026-10-31 Sat	100	—	unknown	18:55–00:50 (good, 5.92 h)	87.3° 18:40	10.47	60%	110.8°
2026-11-01 Sun	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.3° 18:35	10.5	49%	116.7°
2026-11-02 Mon	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.3° 18:35	10.54	38%	121.0°
2026-11-03 Tue	100	—	unknown	18:50–00:50 (good, 6.0 h)	87.3° 18:30	10.57	28%	123.5°
2026-11-04 Wed	100	—	unknown	18:50–00:45 (good, 5.92 h)	87.3° 18:25	10.61	19%	123.9°
2026-11-05 Thu	100	—	unknown	18:50–00:40 (good, 5.83 h)	87.3° 18:20	10.64	12%	122.2°
2026-11-06 Fri	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.3° 18:15	10.68	6%	118.9°
2026-11-07 Sat	100	—	unknown	18:45–00:35 (good, 5.83 h)	87.3° 18:15	10.71	2%	114.1°
2026-11-08 Sun	100	—	unknown	18:45–00:30 (good, 5.75 h)	87.3° 18:10	10.74	0%	108.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-10-10&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.