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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.

2029-04-11astronomy score per night — click a bar for that night2029-05-10
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2029-04-11 Wed 0 — unknown — 79.1° 13:35 7.51 4% 34.7°
2029-04-12 Thu 0 — unknown — 79.1° 13:35 7.45 1% 24.6°
2029-04-13 Fri 0 — unknown — 79.1° 13:30 7.39 0% 16.9°
2029-04-14 Sat 0 — unknown — 79.1° 13:25 7.33 1% 15.3°
2029-04-15 Sun 0 — unknown — 79.1° 13:20 7.28 4% 21.5°
2029-04-16 Mon 0 — unknown — 79.1° 13:15 7.22 8% 31.2°
2029-04-17 Tue 0 — unknown — 79.1° 13:15 7.16 14% 42.1°
2029-04-18 Wed 0 — unknown — 79.1° 13:10 7.1 22% 53.7°
2029-04-19 Thu 0 — unknown — 79.1° 13:05 7.05 31% 65.7°
2029-04-20 Fri 0 — unknown — 79.1° 13:00 6.99 40% 78.1°
2029-04-21 Sat 0 — unknown — 79.1° 13:00 6.93 51% 90.8°
2029-04-22 Sun 0 — unknown — 79.1° 12:55 6.87 62% 104.0°
2029-04-23 Mon 0 — unknown — 79.1° 12:50 6.81 73% 117.5°
2029-04-24 Tue 0 — unknown — 79.1° 12:45 6.75 82% 131.2°
2029-04-25 Wed 0 — unknown — 79.1° 12:40 6.7 90% 144.8°
2029-04-26 Thu 0 — unknown — 79.1° 12:40 6.64 96% 157.4°
2029-04-27 Fri 0 — unknown — 79.1° 12:35 6.58 99% 165.0°
2029-04-28 Sat 0 — unknown — 79.1° 12:30 6.52 100% 160.3°
2029-04-29 Sun 0 — unknown — 79.1° 12:25 6.46 97% 148.5°
2029-04-30 Mon 0 — unknown — 79.1° 12:20 6.41 91% 135.2°
2029-05-01 Tue 0 — unknown — 79.1° 12:20 6.35 84% 121.8°
2029-05-02 Wed 0 — unknown — 79.1° 12:15 6.29 75% 108.7°
2029-05-03 Thu 0 — unknown — 79.1° 12:10 6.23 65% 95.9°
2029-05-04 Fri 0 — unknown — 79.1° 12:05 6.17 55% 83.5°
2029-05-05 Sat 0 — unknown — 79.1° 12:00 6.12 45% 71.5°
2029-05-06 Sun 0 — unknown — 79.1° 11:55 6.06 35% 59.8°
2029-05-07 Mon 0 — unknown — 79.1° 11:50 6.0 26% 48.4°
2029-05-08 Tue 0 — unknown — 79.1° 11:45 5.95 19% 37.4°
2029-05-09 Wed 0 — unknown — 79.1° 11:45 5.89 12% 27.1°
2029-05-10 Thu 0 — unknown — 79.1° 11:40 5.83 6% 18.4°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-04-11&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.