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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: 03-20 (1), 03-21 (1), 03-22 (1) — by astronomy; check the weather when the night is within four days.
2026-03-20astronomy score per night — click a bar for that night2026-04-18
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2026-03-20 Fri 1 0 0 — 79.1° 14:05 8.72 5% 17.5°
2026-03-21 Sat 1 0 0 — 79.1° 14:00 8.67 11% 16.0°
2026-03-22 Sun 1 0 0 — 79.1° 13:55 8.62 19% 24.8°
2026-03-23 Mon 0 0 0 — 79.1° 13:50 8.57 29% 37.1°
2026-03-24 Tue 0 0 0 — 79.1° 13:50 8.51 40% 50.3°
2026-03-25 Wed 0 98 0 — 79.1° 13:45 8.46 52% 63.7°
2026-03-26 Thu 0 51 0 — 79.1° 13:40 8.41 63% 77.1°
2026-03-27 Fri 0 0 0 — 79.1° 13:35 8.35 73% 90.4°
2026-03-28 Sat 0 73 0 — 79.1° 13:35 8.3 82% 103.5°
2026-03-29 Sun 0 0 0 — 79.1° 14:30 8.25 90% 116.3°
2026-03-30 Mon 0 0 0 — 79.1° 14:25 8.19 95% 128.9°
2026-03-31 Tue 0 30 0 — 79.1° 14:20 8.14 99% 140.9°
2026-04-01 Wed 0 0 0 — 79.1° 14:15 8.08 100% 152.1°
2026-04-02 Thu 0 0 0 — 79.1° 14:15 8.03 99% 161.3°
2026-04-03 Fri 0 0 0 — 79.1° 14:10 7.97 96% 164.8°
2026-04-04 Sat 0 0 0 — 79.1° 14:05 7.92 92% 159.9°
2026-04-05 Sun 0 0 0 — 79.1° 14:00 7.86 86% 150.8°
2026-04-06 Mon 0 0 0 — 79.1° 13:55 7.8 79% 140.3°
2026-04-07 Tue 0 0 0 — 79.1° 13:55 7.75 71% 129.3°
2026-04-08 Wed 0 0 0 — 79.1° 13:50 7.69 62% 118.0°
2026-04-09 Thu 0 0 0 — 79.1° 13:45 7.64 53% 106.6°
2026-04-10 Fri 0 0 0 — 79.1° 13:40 7.58 43% 94.9°
2026-04-11 Sat 0 0 0 — 79.1° 13:40 7.52 33% 82.9°
2026-04-12 Sun 0 0 0 — 79.1° 13:35 7.47 24% 70.7°
2026-04-13 Mon 0 0 0 — 79.1° 13:30 7.41 16% 58.1°
2026-04-14 Tue 0 0 0 — 79.1° 13:25 7.35 9% 45.3°
2026-04-15 Wed 0 0 0 — 79.1° 13:20 7.29 3% 32.6°
2026-04-16 Thu 0 0 0 — 79.1° 13:20 7.24 0% 21.0°
2026-04-17 Fri 0 0 0 — 79.1° 13:15 7.18 0% 15.1°
2026-04-18 Sat 0 0 0 — 79.1° 13:10 7.12 3% 21.0°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-03-20&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.