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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.

Best nights for Triangulum Pinwheel: 05-30 (1), 05-31 (1), 06-01 (1), 06-02 (1), 06-03 (1) — by astronomy; check the weather when the night is within four days.
2026-05-10astronomy score per night — click a bar for that night2026-06-08
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2026-05-10 Sun 0 0 0 — 79.1° 11:40 5.85 40% 62.7°
2026-05-11 Mon 0 0 0 — 79.1° 11:35 5.79 30% 50.3°
2026-05-12 Tue 0 0 0 — 79.1° 11:30 5.74 20% 37.8°
2026-05-13 Wed 0 0 0 — 79.1° 11:30 5.68 12% 25.7°
2026-05-14 Thu 0 0 0 — 79.1° 11:25 5.63 5% 16.4°
2026-05-15 Fri 0 0 0 — 79.1° 11:20 5.58 1% 17.2°
2026-05-16 Sat 0 99 0 — 79.1° 11:15 5.52 0% 27.6°
2026-05-17 Sun 0 0 0 — 79.1° 11:10 5.47 2% 41.0°
2026-05-18 Mon 0 0 0 — 79.1° 11:10 5.42 7% 55.1°
2026-05-19 Tue 0 0 0 — 79.1° 11:05 5.37 14% 69.3°
2026-05-20 Wed 0 62 0 — 79.1° 11:00 5.32 23% 83.4°
2026-05-21 Thu 0 0 0 — 79.1° 10:55 5.27 33% 97.1°
2026-05-22 Fri 0 0 0 — 79.1° 10:55 5.22 44% 110.3°
2026-05-23 Sat 0 45 0 — 79.1° 10:50 5.17 55% 123.1°
2026-05-24 Sun 0 81 0 — 79.1° 10:45 5.13 65% 135.3°
2026-05-25 Mon 0 58 0 — 79.1° 10:40 5.08 74% 146.8°
2026-05-26 Tue 0 94 0 — 79.1° 10:35 5.04 83% 157.1°
2026-05-27 Wed 0 95 0 — 79.1° 10:35 4.99 89% 164.1°
2026-05-28 Thu 0 100 0 — 79.1° 10:30 4.95 94% 163.5°
2026-05-29 Fri 0 93 0 — 79.1° 10:25 4.91 98% 156.1°
2026-05-30 Sat 1 61 1 — 79.1° 10:20 4.87 100% 146.1°
2026-05-31 Sun 1 92 1 — 79.1° 10:15 4.83 100% 135.3°
2026-06-01 Mon 1 74 1 — 79.1° 10:15 4.79 98% 124.2°
2026-06-02 Tue 1 79 1 — 79.1° 10:10 4.76 94% 112.9°
2026-06-03 Wed 1 46 0 — 79.1° 10:05 4.73 89% 101.4°
2026-06-04 Thu 1 37 0 — 79.1° 10:00 4.69 82% 89.8°
2026-06-05 Fri 1 93 1 — 79.1° 10:00 4.66 74% 78.1°
2026-06-06 Sat 1 98 1 — 79.1° 09:55 4.63 65% 66.2°
2026-06-07 Sun 1 99 1 — 79.1° 09:50 4.61 55% 54.1°
2026-06-08 Mon 1 3 0 — 79.1° 09:45 4.58 45% 41.9°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-05-10&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.