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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: 11-15 (9), 11-16 (9), 11-13 (8), 11-14 (8), 11-17 (8) — by astronomy; check the weather when the night is within four days.
2035-10-22astronomy score per night — click a bar for that night2035-11-20
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2035-10-22 Mon 0 — unknown — 50.2° 11:45 10.11 61% 79.4°
2035-10-23 Tue 0 — unknown — 50.2° 11:40 10.15 50% 65.3°
2035-10-24 Wed 0 — unknown — 50.2° 11:40 10.19 38% 51.3°
2035-10-25 Thu 0 — unknown — 50.2° 11:35 10.23 28% 37.5°
2035-10-26 Fri 0 — unknown — 50.2° 11:30 10.27 19% 23.9°
2035-10-27 Sat 0 — unknown — 50.2° 10:25 10.31 11% 10.5°
2035-10-28 Sun 0 — unknown — 50.2° 10:20 10.35 5% 3.6°
2035-10-29 Mon 0 — unknown — 50.2° 10:20 10.38 2% 16.1°
2035-10-30 Tue 0 — unknown — 50.2° 10:15 10.42 0% 28.9°
2035-10-31 Wed 0 — unknown — 50.2° 10:10 10.46 1% 41.5°
2035-11-01 Thu 0 — unknown — 50.2° 10:05 10.49 3% 53.9°
2035-11-02 Fri 0 — unknown — 50.2° 10:00 10.53 8% 66.1°
2035-11-03 Sat 1 — unknown — 50.2° 10:00 10.57 14% 78.1°
2035-11-04 Sun 1 — unknown — 50.2° 09:55 10.6 21% 90.0°
2035-11-05 Mon 1 — unknown — 50.2° 09:50 10.64 29% 101.8°
2035-11-06 Tue 1 — unknown — 50.2° 09:45 10.67 38% 113.6°
2035-11-07 Wed 1 — unknown 05:55–06:00 (marginal, 0.08 h) 50.2° 09:45 10.7 47% 125.5°
2035-11-08 Thu 3 — unknown 05:50–06:00 (marginal, 0.17 h) 50.2° 09:40 10.74 56% 137.6°
2035-11-09 Fri 3 — unknown 05:50–06:05 (marginal, 0.25 h) 50.2° 09:35 10.77 66% 149.9°
2035-11-10 Sat 4 — unknown 05:15–05:30 (marginal, 0.25 h) 50.2° 09:30 10.8 75% 162.5°
2035-11-11 Sun 6 — unknown 05:10–05:35 (marginal, 0.42 h) 50.2° 09:25 10.83 84% 175.2°
2035-11-12 Mon 7 — unknown 05:10–06:05 (marginal, 0.92 h) 50.2° 09:25 10.86 91% 170.6°
2035-11-13 Tue 8 — unknown 05:30–05:35 (good, 0.08 h) 50.2° 09:20 10.89 96% 156.9°
2035-11-14 Wed 8 — unknown 05:00–06:10 (marginal, 1.17 h) 50.2° 09:15 10.92 99% 142.6°
2035-11-15 Thu 9 — unknown 04:55–06:10 (marginal, 1.25 h) 50.2° 09:10 10.95 100% 128.0°
2035-11-16 Fri 9 — unknown 05:35–05:40 (good, 0.08 h) 50.2° 09:05 10.98 97% 113.2°
2035-11-17 Sat 8 — unknown 04:50–05:40 (marginal, 0.83 h) 50.2° 09:05 11.01 92% 98.3°
2035-11-18 Sun 8 — unknown 04:50–05:40 (marginal, 0.83 h) 50.2° 09:00 11.04 84% 83.6°
2035-11-19 Mon 7 — unknown 04:50–05:40 (marginal, 0.83 h) 50.2° 08:55 11.06 75% 68.9°
2035-11-20 Tue 8 — unknown 04:50–05:40 (marginal, 0.83 h) 50.2° 08:50 11.09 64% 54.6°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-10-22&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.