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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.

2026-08-12astronomy score per night — click a bar for that night2026-09-10
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2026-08-12 Wed 0 0 0 — 50.2° 16:25 6.47 0% 43.1°
2026-08-13 Thu 0 0 0 — 50.2° 16:25 6.53 2% 29.2°
2026-08-14 Fri 0 0 0 — 50.2° 16:20 6.58 6% 16.3°
2026-08-15 Sat 0 0 0 — 50.2° 16:15 6.64 12% 7.9°
2026-08-16 Sun 0 0 0 — 50.2° 16:10 6.7 20% 14.6°
2026-08-17 Mon 0 0 0 — 50.2° 16:10 6.76 29% 26.2°
2026-08-18 Tue 0 0 0 — 50.2° 16:05 6.81 39% 38.1°
2026-08-19 Wed 0 0 0 — 50.2° 16:00 6.87 48% 50.0°
2026-08-20 Thu 0 0 0 — 50.2° 15:55 6.93 58% 61.8°
2026-08-21 Fri 0 0 0 — 50.2° 15:50 6.99 67% 73.5°
2026-08-22 Sat 0 0 0 — 50.2° 15:50 7.04 76% 85.2°
2026-08-23 Sun 0 0 0 — 50.2° 15:45 7.1 83% 97.0°
2026-08-24 Mon 0 0 0 — 50.2° 15:40 7.16 90% 108.9°
2026-08-25 Tue 0 0 0 — 50.2° 15:35 7.22 95% 121.0°
2026-08-26 Wed 0 0 0 — 50.2° 15:30 7.27 98% 133.2°
2026-08-27 Thu 0 0 0 — 50.2° 15:30 7.33 100% 145.5°
2026-08-28 Fri 0 0 0 — 50.2° 15:25 7.39 99% 157.8°
2026-08-29 Sat 0 0 0 — 50.2° 15:20 7.44 97% 169.0°
2026-08-30 Sun 0 0 0 — 50.2° 15:15 7.5 92% 170.3°
2026-08-31 Mon 0 0 0 — 50.2° 15:15 7.56 85% 159.3°
2026-09-01 Tue 0 0 0 — 50.2° 15:10 7.61 76% 146.3°
2026-09-02 Wed 0 0 0 — 50.2° 15:05 7.67 66% 132.7°
2026-09-03 Thu 0 0 0 — 50.2° 15:00 7.72 55% 118.9°
2026-09-04 Fri 0 0 0 — 50.2° 14:55 7.78 43% 105.0°
2026-09-05 Sat 0 0 0 — 50.2° 14:55 7.83 32% 90.9°
2026-09-06 Sun 0 0 0 — 50.2° 14:50 7.89 22% 76.7°
2026-09-07 Mon 0 0 0 — 50.2° 14:45 7.94 13% 62.5°
2026-09-08 Tue 0 0 0 — 50.2° 14:40 8.0 6% 48.4°
2026-09-09 Wed 0 0 0 — 50.2° 14:35 8.05 2% 34.6°
2026-09-10 Thu 0 0 0 — 50.2° 14:35 8.11 0% 21.3°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-08-12&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.