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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 Andromeda Galaxy: 05-11 (3), 05-12 (3), 05-06 (2), 05-07 (2), 05-08 (2) — by astronomy; check the weather when the night is within four days.
2035-04-13astronomy score per night — click a bar for that night2035-05-12
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2035-04-13 Fri 0 — unknown — 89.8° 12:40 7.42 37% 76.4°
2035-04-14 Sat 0 — unknown — 89.7° 12:35 7.36 48% 87.6°
2035-04-15 Sun 0 — unknown — 89.5° 12:30 7.3 59% 98.7°
2035-04-16 Mon 0 — unknown — 89.6° 12:30 7.25 70% 109.4°
2035-04-17 Tue 0 — unknown — 89.7° 12:25 7.19 79% 119.5°
2035-04-18 Wed 0 — unknown — 89.8° 12:20 7.13 87% 128.5°
2035-04-19 Thu 0 — unknown — 89.6° 12:15 7.07 93% 136.0°
2035-04-20 Fri 0 — unknown — 89.5° 12:15 7.01 97% 141.2°
2035-04-21 Sat 0 — unknown — 89.7° 12:10 6.96 100% 143.2°
2035-04-22 Sun 0 — unknown — 89.8° 12:05 6.9 100% 141.6°
2035-04-23 Mon 0 — unknown — 89.7° 12:00 6.84 98% 137.0°
2035-04-24 Tue 0 — unknown — 89.5° 11:55 6.78 94% 130.3°
2035-04-25 Wed 0 — unknown — 89.7° 11:50 6.72 90% 122.4°
2035-04-26 Thu 0 — unknown — 89.8° 11:45 6.67 83% 113.8°
2035-04-27 Fri 0 — unknown — 89.7° 11:40 6.61 75% 104.6°
2035-04-28 Sat 0 — unknown — 89.5° 11:35 6.55 67% 95.2°
2035-04-29 Sun 1 — unknown — 89.6° 11:35 6.49 57% 85.7°
2035-04-30 Mon 1 — unknown — 89.7° 11:30 6.43 48% 76.0°
2035-05-01 Tue 1 — unknown — 89.8° 11:25 6.37 38% 66.4°
2035-05-02 Wed 1 — unknown — 89.6° 11:20 6.32 28% 57.0°
2035-05-03 Thu 1 — unknown — 89.5° 11:15 6.26 19% 48.4°
2035-05-04 Fri 1 — unknown — 89.6° 11:15 6.2 11% 41.4°
2035-05-05 Sat 1 — unknown — 89.8° 11:10 6.14 5% 37.3°
2035-05-06 Sun 2 — unknown 05:00–05:05 (marginal, 0.08 h) 89.7° 11:05 6.09 1% 37.7°
2035-05-07 Mon 2 — unknown 05:00–05:05 (marginal, 0.08 h) 89.6° 11:00 6.03 0% 42.7°
2035-05-08 Tue 2 — unknown 04:55–05:00 (marginal, 0.08 h) 89.5° 11:00 5.97 2% 51.1°
2035-05-09 Wed 2 — unknown 04:50–05:00 (marginal, 0.17 h) 89.7° 10:55 5.92 7% 61.4°
2035-05-10 Thu 2 — unknown 04:45–05:00 (marginal, 0.25 h) 89.8° 10:50 5.86 14% 72.7°
2035-05-11 Fri 3 — unknown 04:40–04:55 (marginal, 0.25 h) 89.7° 10:45 5.81 23% 84.3°
2035-05-12 Sat 3 — unknown 04:40–04:55 (marginal, 0.25 h) 89.5° 10:40 5.75 33% 95.7°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-04-13&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.