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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.

2045-09-14astronomy score per night — click a bar for that night2045-10-13
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2045-09-14 Thu 0 — unknown — 50.1° 14:15 8.34 20% 40.1°
2045-09-15 Fri 0 — unknown — 50.1° 14:15 8.39 29% 53.2°
2045-09-16 Sat 0 — unknown — 50.1° 14:10 8.45 39% 66.0°
2045-09-17 Sun 0 — unknown — 50.1° 14:05 8.5 49% 78.5°
2045-09-18 Mon 0 — unknown — 50.1° 14:00 8.55 58% 90.6°
2045-09-19 Tue 0 — unknown — 50.1° 13:55 8.6 68% 102.5°
2045-09-20 Wed 0 — unknown — 50.1° 13:55 8.65 76% 114.3°
2045-09-21 Thu 0 — unknown — 50.1° 13:50 8.7 84% 126.0°
2045-09-22 Fri 0 — unknown — 50.1° 13:45 8.75 90% 137.6°
2045-09-23 Sat 0 — unknown — 50.1° 13:40 8.81 95% 149.1°
2045-09-24 Sun 0 — unknown — 50.1° 13:40 8.86 98% 160.3°
2045-09-25 Mon 0 — unknown — 50.1° 13:35 8.91 100% 169.9°
2045-09-26 Tue 0 — unknown — 50.1° 13:30 8.96 100% 169.5°
2045-09-27 Wed 0 — unknown — 50.1° 13:25 9.0 97% 159.5°
2045-09-28 Thu 0 — unknown — 50.1° 13:20 9.05 93% 147.7°
2045-09-29 Fri 0 — unknown — 50.1° 13:20 9.1 87% 135.3°
2045-09-30 Sat 0 — unknown — 50.1° 13:15 9.15 79% 122.5°
2045-10-01 Sun 0 — unknown — 50.1° 13:10 9.2 70% 109.5°
2045-10-02 Mon 0 — unknown — 50.1° 13:05 9.25 59% 96.2°
2045-10-03 Tue 0 — unknown — 50.1° 13:00 9.29 48% 82.6°
2045-10-04 Wed 0 — unknown — 50.1° 13:00 9.34 37% 68.7°
2045-10-05 Thu 0 — unknown — 50.1° 12:55 9.39 26% 54.6°
2045-10-06 Fri 0 — unknown — 50.1° 12:50 9.43 17% 40.4°
2045-10-07 Sat 0 — unknown — 50.1° 12:45 9.48 9% 26.2°
2045-10-08 Sun 0 — unknown — 50.1° 12:45 9.53 3% 13.1°
2045-10-09 Mon 0 — unknown — 50.1° 12:40 9.57 0% 9.5°
2045-10-10 Tue 0 — unknown — 50.1° 12:35 9.62 0% 20.8°
2045-10-11 Wed 0 — unknown — 50.1° 12:30 9.66 3% 34.3°
2045-10-12 Thu 0 — unknown — 50.1° 12:25 9.71 8% 47.8°
2045-10-13 Fri 0 — unknown — 50.1° 12:25 9.75 15% 61.1°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-09-14&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.