← 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.

2028-04-10astronomy score per night — click a bar for that night2028-05-09
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2028-04-10 Mon 0 — unknown — 79.1° 13:40 7.55 97% 163.2°
2028-04-11 Tue 0 — unknown — 79.1° 13:35 7.49 92% 153.3°
2028-04-12 Wed 0 — unknown — 79.1° 13:30 7.44 85% 141.2°
2028-04-13 Thu 0 — unknown — 79.1° 13:30 7.38 76% 128.9°
2028-04-14 Fri 0 — unknown — 79.1° 13:25 7.32 67% 116.7°
2028-04-15 Sat 0 — unknown — 79.1° 13:20 7.26 57% 104.7°
2028-04-16 Sun 0 — unknown — 79.1° 13:15 7.21 48% 92.9°
2028-04-17 Mon 0 — unknown — 79.1° 13:10 7.15 38% 81.4°
2028-04-18 Tue 0 — unknown — 79.1° 13:10 7.09 29% 69.9°
2028-04-19 Wed 0 — unknown — 79.1° 13:05 7.03 21% 58.5°
2028-04-20 Thu 0 — unknown — 79.1° 13:00 6.97 14% 47.3°
2028-04-21 Fri 0 — unknown — 79.1° 12:55 6.92 8% 36.2°
2028-04-22 Sat 0 — unknown — 79.1° 12:55 6.86 4% 25.7°
2028-04-23 Sun 0 — unknown — 79.1° 12:50 6.8 1% 17.0°
2028-04-24 Mon 0 — unknown — 79.1° 12:45 6.74 0% 14.8°
2028-04-25 Tue 0 — unknown — 79.1° 12:40 6.68 1% 21.5°
2028-04-26 Wed 0 — unknown — 79.1° 12:35 6.62 5% 32.1°
2028-04-27 Thu 0 — unknown — 79.1° 12:35 6.57 10% 44.1°
2028-04-28 Fri 0 — unknown — 79.1° 12:30 6.51 18% 56.8°
2028-04-29 Sat 0 — unknown — 79.1° 12:25 6.45 27% 69.8°
2028-04-30 Sun 0 — unknown — 79.1° 12:20 6.39 37% 83.1°
2028-05-01 Mon 0 — unknown — 79.1° 12:15 6.33 48% 96.6°
2028-05-02 Tue 0 — unknown — 79.1° 12:15 6.28 59% 110.2°
2028-05-03 Wed 0 — unknown — 79.1° 12:10 6.22 70% 124.0°
2028-05-04 Thu 0 — unknown — 79.1° 12:05 6.16 80% 137.6°
2028-05-05 Fri 0 — unknown — 79.1° 12:00 6.1 89% 150.6°
2028-05-06 Sat 0 — unknown — 79.1° 11:55 6.05 95% 161.7°
2028-05-07 Sun 0 — unknown — 79.1° 11:50 5.99 99% 165.3°
2028-05-08 Mon 0 — unknown — 79.1° 11:45 5.93 100% 157.8°
2028-05-09 Tue 0 — unknown — 79.1° 11:40 5.88 98% 146.2°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-04-10&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.