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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: 06-09 (3), 06-10 (3), 06-11 (3), 06-05 (2), 06-06 (2) — by astronomy; check the weather when the night is within four days.
2030-05-13astronomy score per night — click a bar for that night2030-06-11
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2030-05-13 Mon 0 — unknown — 79.1° 11:30 5.68 82% 147.9°
2030-05-14 Tue 0 — unknown — 79.1° 11:25 5.63 90% 159.2°
2030-05-15 Wed 0 — unknown — 79.1° 11:20 5.58 96% 164.2°
2030-05-16 Thu 0 — unknown — 79.1° 11:15 5.52 100% 157.5°
2030-05-17 Fri 0 — unknown — 79.1° 11:10 5.47 100% 145.2°
2030-05-18 Sat 0 — unknown — 79.1° 11:10 5.42 97% 131.3°
2030-05-19 Sun 0 — unknown — 79.1° 11:05 5.37 91% 117.2°
2030-05-20 Mon 0 — unknown — 79.1° 11:00 5.32 83% 103.2°
2030-05-21 Tue 0 — unknown — 79.1° 10:55 5.27 74% 89.5°
2030-05-22 Wed 0 — unknown — 79.1° 10:55 5.22 64% 76.3°
2030-05-23 Thu 0 — unknown — 79.1° 10:50 5.17 53% 63.6°
2030-05-24 Fri 0 — unknown — 79.1° 10:45 5.13 43% 51.4°
2030-05-25 Sat 0 — unknown — 79.1° 10:40 5.08 33% 39.8°
2030-05-26 Sun 0 — unknown — 79.1° 10:35 5.04 24% 29.1°
2030-05-27 Mon 0 — unknown — 79.1° 10:35 4.99 16% 20.1°
2030-05-28 Tue 0 — unknown — 79.1° 10:30 4.95 10% 15.7°
2030-05-29 Wed 0 — unknown — 79.1° 10:25 4.91 5% 19.2°
2030-05-30 Thu 1 — unknown — 79.1° 10:20 4.87 2% 27.6°
2030-05-31 Fri 1 — unknown — 79.1° 10:15 4.83 0% 37.8°
2030-06-01 Sat 1 — unknown — 79.1° 10:15 4.79 0% 48.6°
2030-06-02 Sun 1 — unknown — 79.1° 10:10 4.76 2% 59.9°
2030-06-03 Mon 1 — unknown — 79.1° 10:05 4.73 6% 71.3°
2030-06-04 Tue 1 — unknown — 79.1° 10:00 4.69 12% 83.0°
2030-06-05 Wed 2 — unknown 04:30–04:35 (marginal, 0.08 h) 79.1° 10:00 4.66 19% 94.8°
2030-06-06 Thu 2 — unknown 04:25–04:35 (marginal, 0.17 h) 79.1° 09:55 4.63 28% 106.9°
2030-06-07 Fri 2 — unknown 04:25–04:30 (marginal, 0.08 h) 79.1° 09:50 4.61 37% 119.1°
2030-06-08 Sat 2 — unknown 04:20–04:30 (marginal, 0.17 h) 79.1° 09:45 4.58 48% 131.4°
2030-06-09 Sun 3 — unknown 04:15–04:30 (marginal, 0.25 h) 79.1° 09:40 4.56 58% 143.8°
2030-06-10 Mon 3 — unknown 04:10–04:30 (marginal, 0.33 h) 79.1° 09:40 4.53 69% 155.4°
2030-06-11 Tue 3 — unknown 04:05–04:30 (marginal, 0.42 h) 79.1° 09:35 4.51 79% 163.6°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-05-13&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.