← 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.

2026-04-26astronomy score per night — click a bar for that night2026-05-25
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2026-04-26 Sun 0 0 0 — 72.5° 14:50 6.65 78% 101.8°
2026-04-27 Mon 0 0 0 — 72.5° 14:45 6.6 86% 114.6°
2026-04-28 Tue 0 0 0 — 72.5° 14:45 6.54 92% 127.3°
2026-04-29 Wed 0 0 0 — 72.5° 14:40 6.48 97% 139.7°
2026-04-30 Thu 0 0 0 — 72.5° 14:35 6.42 99% 152.0°
2026-05-01 Fri 0 0 0 — 72.5° 14:30 6.36 100% 164.1°
2026-05-02 Sat 0 0 0 — 72.5° 14:25 6.31 98% 176.0°
2026-05-03 Sun 0 0 0 — 72.5° 14:25 6.25 95% 171.9°
2026-05-04 Mon 0 0 0 — 72.5° 14:20 6.19 91% 160.1°
2026-05-05 Tue 0 0 0 — 72.5° 14:15 6.13 84% 148.3°
2026-05-06 Wed 0 0 0 — 72.5° 14:10 6.08 77% 136.4°
2026-05-07 Thu 0 0 0 — 72.5° 14:10 6.02 69% 124.5°
2026-05-08 Fri 0 0 0 — 72.5° 14:05 5.96 59% 112.4°
2026-05-09 Sat 0 0 0 — 72.5° 14:00 5.91 50% 100.0°
2026-05-10 Sun 0 0 0 — 72.5° 13:55 5.85 40% 87.3°
2026-05-11 Mon 0 0 0 — 72.5° 13:50 5.79 30% 74.3°
2026-05-12 Tue 0 0 0 — 72.5° 13:50 5.74 20% 60.7°
2026-05-13 Wed 0 0 0 — 72.5° 13:45 5.68 12% 46.7°
2026-05-14 Thu 0 0 0 — 72.5° 13:40 5.63 5% 32.3°
2026-05-15 Fri 0 0 0 — 72.5° 13:35 5.58 1% 17.4°
2026-05-16 Sat 0 0 0 — 72.5° 13:30 5.52 0% 2.5°
2026-05-17 Sun 0 0 0 — 72.5° 13:30 5.47 2% 12.9°
2026-05-18 Mon 0 0 0 — 72.5° 13:25 5.42 7% 28.0°
2026-05-19 Tue 0 0 0 — 72.5° 13:20 5.37 14% 42.9°
2026-05-20 Wed 0 0 0 — 72.5° 13:15 5.32 23% 57.4°
2026-05-21 Thu 0 0 0 — 72.5° 13:15 5.27 33% 71.6°
2026-05-22 Fri 0 0 0 — 72.5° 13:10 5.22 44% 85.3°
2026-05-23 Sat 0 0 0 — 72.5° 13:05 5.17 55% 98.7°
2026-05-24 Sun 0 0 0 — 72.5° 13:00 5.13 65% 111.7°
2026-05-25 Mon 0 0 0 — 72.5° 12:55 5.08 74% 124.3°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-04-26&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.