← 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 Vega: 11-11 (74), 11-12 (72), 11-13 (71), 11-14 (69), 11-15 (67) — by astronomy; check the weather when the night is within four days.
2025-11-11astronomy score per night — click a bar for that night2025-12-10
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2025-11-11 Tue 74 88 65 18:40–21:30 (good, 2.83 h) 87.1° 15:35 10.85 53% 111.6°
2025-11-12 Wed 72 38 28 21:00–21:30 (good, 0.5 h) 87.1° 15:30 10.88 43% 108.6°
2025-11-13 Thu 71 99 70 18:40–21:25 (good, 2.75 h) 87.1° 15:25 10.91 33% 104.8°
2025-11-14 Fri 69 100 69 18:40–21:25 (good, 2.75 h) 87.1° 15:25 10.94 24% 100.5°
2025-11-15 Sat 67 92 62 18:40–20:50 (good, 2.17 h) 87.1° 15:20 10.97 16% 95.8°
2025-11-16 Sun 66 60 40 18:40–19:00 (good, 0.33 h) 87.1° 15:15 10.99 10% 91.0°
2025-11-17 Mon 64 0 0 — 87.1° 15:10 11.02 5% 86.1°
2025-11-18 Tue 62 0 0 — 87.1° 15:10 11.05 2% 81.5°
2025-11-19 Wed 62 4 2 — 87.1° 15:05 11.08 0% 77.1°
2025-11-20 Thu 60 10 6 — 87.1° 15:00 11.1 0% 73.3°
2025-11-21 Fri 58 1 0 — 87.1° 14:55 11.13 3% 70.1°
2025-11-22 Sat 57 49 28 20:00–20:30 (good, 0.5 h) 87.1° 14:50 11.15 6% 67.7°
2025-11-23 Sun 54 96 52 18:35–20:45 (good, 2.17 h) 87.1° 14:50 11.17 12% 66.3°
2025-11-24 Mon 49 98 48 18:35–20:40 (good, 2.08 h) 87.1° 14:45 11.2 18% 65.9°
2025-11-25 Tue 43 0 0 — 87.1° 14:40 11.22 27% 66.8°
2025-11-26 Wed 38 2 1 — 87.1° 14:35 11.24 36% 68.8°
2025-11-27 Thu 33 0 0 — 87.1° 14:30 11.26 46% 71.9°
2025-11-28 Fri 29 0 0 — 87.1° 14:30 11.28 57% 76.0°
2025-11-29 Sat 26 0 0 — 87.1° 14:25 11.3 67% 80.9°
2025-11-30 Sun 23 0 0 — 87.1° 14:20 11.32 78% 86.5°
2025-12-01 Mon 23 90 21 18:35–20:40 (marginal, 2.08 h) 87.1° 14:15 11.34 86% 92.4°
2025-12-02 Tue 23 0 0 — 87.1° 14:10 11.35 94% 98.4°
2025-12-03 Wed 24 26 6 18:35–19:00 (marginal, 0.42 h) 87.1° 14:10 11.37 98% 103.9°
2025-12-04 Thu 26 0 0 — 87.1° 14:05 11.38 100% 108.6°
2025-12-05 Fri 27 0 0 — 87.1° 14:00 11.4 98% 112.0°
2025-12-06 Sat 29 0 0 — 87.1° 13:55 11.41 94% 113.9°
2025-12-07 Sun 33 11 4 — 87.1° 13:55 11.42 88% 114.0°
2025-12-08 Mon 33 63 21 19:00–19:20 (good, 0.33 h) 87.1° 13:50 11.44 79% 112.6°
2025-12-09 Tue 31 1 0 — 87.1° 13:45 11.45 70% 109.9°
2025-12-10 Wed 29 7 2 — 87.1° 13:40 11.46 60% 106.2°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2025-11-11&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.