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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 3C 273: 11-26 (30), 11-25 (28), 11-24 (27), 11-23 (26), 11-22 (24) — by astronomy; check the weather when the night is within four days.
2025-10-28astronomy score per night — click a bar for that night2025-11-26
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2025-10-28 Tue 0 100 0 — 50.2° 10:20 10.36 42% 111.3°
2025-10-29 Wed 0 100 0 — 50.2° 10:15 10.4 52% 123.8°
2025-10-30 Thu 0 0 0 — 50.2° 10:10 10.44 63% 136.6°
2025-10-31 Fri 0 99 0 — 50.2° 10:10 10.47 73% 149.7°
2025-11-01 Sat 0 98 0 — 50.2° 10:05 10.51 82% 162.9°
2025-11-02 Sun 1 93 1 — 50.2° 10:00 10.55 90% 173.4°
2025-11-03 Mon 1 0 0 — 50.2° 09:55 10.58 96% 165.3°
2025-11-04 Tue 1 0 0 — 50.2° 09:50 10.62 99% 151.0°
2025-11-05 Wed 1 0 0 — 50.2° 09:50 10.65 100% 136.0°
2025-11-06 Thu 1 0 0 — 50.2° 09:45 10.69 97% 120.9°
2025-11-07 Fri 2 0 0 — 50.2° 09:40 10.72 92% 105.9°
2025-11-08 Sat 2 0 0 — 50.2° 09:35 10.75 84% 91.2°
2025-11-09 Sun 2 0 0 — 50.2° 09:35 10.78 74% 76.9°
2025-11-10 Mon 2 0 0 — 50.2° 09:30 10.82 64% 63.1°
2025-11-11 Tue 3 99 3 05:15–05:35 (marginal, 0.33 h) 50.2° 09:25 10.85 53% 49.8°
2025-11-12 Wed 4 98 4 05:10–05:35 (marginal, 0.42 h) 50.2° 09:20 10.88 43% 36.9°
2025-11-13 Thu 5 31 2 — 50.2° 09:15 10.91 33% 24.5°
2025-11-14 Fri 7 100 7 05:00–05:35 (marginal, 0.58 h) 50.2° 09:15 10.94 24% 13.0°
2025-11-15 Sat 9 78 7 04:55–05:35 (marginal, 0.67 h) 50.2° 09:10 10.97 16% 6.5°
2025-11-16 Sun 13 41 5 05:25–05:40 (marginal, 0.25 h) 50.2° 09:05 10.99 10% 14.5°
2025-11-17 Mon 15 0 0 — 50.2° 09:00 11.02 5% 25.7°
2025-11-18 Tue 18 0 0 — 50.2° 08:55 11.05 2% 37.2°
2025-11-19 Wed 19 0 0 — 50.2° 08:55 11.08 0% 48.9°
2025-11-20 Thu 21 0 0 — 50.2° 08:50 11.1 0% 60.6°
2025-11-21 Fri 22 0 0 — 50.2° 08:45 11.13 3% 72.4°
2025-11-22 Sat 24 0 0 — 50.2° 08:40 11.15 6% 84.2°
2025-11-23 Sun 26 100 26 04:50–05:45 (good, 0.92 h) 50.2° 08:40 11.17 12% 96.1°
2025-11-24 Mon 27 0 0 — 50.2° 08:35 11.2 18% 108.2°
2025-11-25 Tue 28 0 0 — 50.2° 08:30 11.22 27% 120.4°
2025-11-26 Wed 30 0 0 — 50.2° 08:25 11.24 36% 132.8°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2025-10-28&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.