← single night · whole-night plan

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: 09-24 (100), 09-25 (100), 09-26 (100), 09-27 (100), 09-28 (100) — by astronomy; check the weather when the night is within four days.
2025-09-24astronomy score per night — click a bar for that night2025-10-23
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2025-09-24 Wed 100 95 95 20:50–04:00 (good, 7.17 h) 87.3° 22:05 8.85 9% 110.4°
2025-09-25 Thu 100 0 0 — 87.3° 22:00 8.9 15% 105.0°
2025-09-26 Fri 100 20 20 00:00–01:00 (good, 1.0 h) 87.3° 22:00 8.95 22% 99.1°
2025-09-27 Sat 100 16 16 20:45–21:00 (good, 0.25 h) 87.3° 21:55 9.0 31% 92.9°
2025-09-28 Sun 100 0 0 — 87.3° 21:50 9.05 40% 86.6°
2025-09-29 Mon 100 0 0 — 87.3° 21:45 9.09 49% 80.3°
2025-09-30 Tue 100 50 50 00:00–04:00 (good, 4.0 h) 87.3° 21:40 9.14 59% 74.2°
2025-10-01 Wed 93 0 0 — 87.3° 21:40 9.19 69% 68.6°
2025-10-02 Thu 85 0 0 — 87.3° 21:35 9.24 78% 63.7°
2025-10-03 Fri 63 0 0 — 87.3° 21:30 9.29 86% 60.0°
2025-10-04 Sat 60 94 56 20:30–04:15 (marginal, 7.75 h) 87.3° 21:25 9.33 93% 58.1°
2025-10-05 Sun 57 56 32 20:30–23:00 (marginal, 2.5 h) 87.3° 21:20 9.38 98% 58.3°
2025-10-06 Mon 57 0 0 — 87.3° 21:20 9.43 100% 60.7°
2025-10-07 Tue 65 0 0 — 87.3° 21:15 9.47 99% 65.2°
2025-10-08 Wed 71 0 0 — 87.3° 21:10 9.52 95% 71.4°
2025-10-09 Thu 78 95 74 20:25–22:45 (good, 2.33 h) 87.3° 21:05 9.57 89% 78.5°
2025-10-10 Fri 100 82 82 20:20–01:05 (good, 4.75 h) 87.3° 21:00 9.61 80% 86.2°
2025-10-11 Sat 100 38 38 20:20–22:00 (good, 1.67 h) 87.3° 21:00 9.66 70% 93.9°
2025-10-12 Sun 100 41 41 01:00–02:55 (good, 1.92 h) 87.3° 20:55 9.7 59% 101.2°
2025-10-13 Mon 100 8 8 — 87.3° 20:50 9.74 48% 107.9°
2025-10-14 Tue 100 0 0 — 87.3° 20:45 9.79 38% 113.5°
2025-10-15 Wed 100 12 12 23:00–00:00 (good, 1.0 h) 87.3° 20:45 9.83 28% 117.9°
2025-10-16 Thu 100 0 0 — 87.3° 20:40 9.87 19% 120.9°
2025-10-17 Fri 100 0 0 — 87.3° 20:35 9.92 12% 122.1°
2025-10-18 Sat 100 0 0 — 87.3° 20:30 9.96 6% 121.7°
2025-10-19 Sun 100 0 0 — 87.3° 20:25 10.0 2% 119.6°
2025-10-20 Mon 100 28 28 20:05–21:00 (good, 0.92 h) 87.3° 20:25 10.04 0% 116.3°
2025-10-21 Tue 100 16 16 23:00–00:00 (marginal, 1.0 h) 87.3° 20:20 10.08 0% 111.8°
2025-10-22 Wed 100 45 45 20:05–00:00 (good, 3.92 h) 87.3° 20:15 10.13 2% 106.6°
2025-10-23 Thu 100 27 27 20:05–22:00 (good, 1.92 h) 87.3° 20:10 10.17 5% 100.8°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2025-09-24&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.