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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 Vega: 12-14 (25), 12-15 (23), 12-16 (23), 12-17 (21), 12-18 (20) — by astronomy; check the weather when the night is within four days.
2036-12-14astronomy score per night — click a bar for that night2037-01-12
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2036-12-14 Sun 25 — unknown 18:35–19:25 (good, 0.83 h) 87.1° 13:25 11.49 8% 69.4°
2036-12-15 Mon 23 — unknown 18:35–19:20 (good, 0.75 h) 87.1° 13:20 11.49 3% 64.7°
2036-12-16 Tue 23 — unknown 18:35–19:15 (good, 0.67 h) 87.1° 13:15 11.5 1% 61.4°
2036-12-17 Wed 21 — unknown 18:35–19:10 (good, 0.58 h) 87.1° 13:15 11.5 0% 59.6°
2036-12-18 Thu 20 — unknown 18:35–19:10 (good, 0.58 h) 87.1° 13:10 11.5 2% 59.5°
2036-12-19 Fri 18 — unknown 18:35–19:05 (good, 0.5 h) 87.1° 13:05 11.51 5% 60.9°
2036-12-20 Sat 16 — unknown 18:35–18:55 (good, 0.33 h) 87.1° 13:00 11.51 10% 63.6°
2036-12-21 Sun 14 — unknown 18:35–18:50 (good, 0.25 h) 87.1° 12:55 11.51 16% 67.5°
2036-12-22 Mon 12 — unknown 18:35–18:45 (good, 0.17 h) 87.1° 12:55 11.51 24% 72.2°
2036-12-23 Tue 10 — unknown 18:40–19:20 (marginal, 0.67 h) 87.1° 12:50 11.5 32% 77.6°
2036-12-24 Wed 9 — unknown 18:40–19:15 (marginal, 0.58 h) 87.1° 12:45 11.5 42% 83.4°
2036-12-25 Thu 8 — unknown 18:40–19:10 (marginal, 0.5 h) 87.1° 12:40 11.5 51% 89.4°
2036-12-26 Fri 8 — unknown 18:40–19:10 (marginal, 0.5 h) 87.1° 12:35 11.49 61% 95.6°
2036-12-27 Sat 7 — unknown 18:40–19:05 (marginal, 0.42 h) 87.1° 12:35 11.49 70% 101.8°
2036-12-28 Sun 7 — unknown 18:40–19:00 (marginal, 0.33 h) 87.1° 12:30 11.48 79% 107.7°
2036-12-29 Mon 8 — unknown 05:55–06:10 (marginal, 0.25 h) 87.1° 12:25 11.47 87% 112.9°
2036-12-30 Tue 8 — unknown 05:50–06:10 (marginal, 0.33 h) 87.1° 12:20 11.47 94% 117.2°
2036-12-31 Wed 7 — unknown 05:50–06:10 (marginal, 0.33 h) 87.1° 12:20 11.46 98% 119.9°
2037-01-01 Thu 8 — unknown 05:45–06:10 (marginal, 0.42 h) 87.1° 12:15 11.45 100% 120.6°
2037-01-02 Fri 8 — unknown 05:40–06:10 (marginal, 0.5 h) 87.1° 12:10 11.44 99% 119.2°
2037-01-03 Sat 8 — unknown 05:35–06:10 (marginal, 0.58 h) 87.1° 12:05 11.42 95% 115.6°
2037-01-04 Sun 8 — unknown 05:30–06:10 (marginal, 0.67 h) 87.1° 12:00 11.41 89% 110.4°
2037-01-05 Mon 8 — unknown 05:30–06:10 (marginal, 0.67 h) 87.1° 11:55 11.4 80% 104.0°
2037-01-06 Tue 9 — unknown 05:25–06:10 (marginal, 0.75 h) 87.1° 11:50 11.38 70% 97.0°
2037-01-07 Wed 10 — unknown 05:20–06:10 (marginal, 0.83 h) 87.1° 11:45 11.37 59% 89.8°
2037-01-08 Thu 11 — unknown 06:05–06:10 (good, 0.08 h) 87.1° 11:40 11.35 48% 82.8°
2037-01-09 Fri 13 — unknown 06:00–06:10 (good, 0.17 h) 87.1° 11:40 11.34 37% 76.3°
2037-01-10 Sat 15 — unknown 05:50–06:10 (good, 0.33 h) 87.1° 11:35 11.32 27% 70.5°
2037-01-11 Sun 17 — unknown 05:40–06:10 (good, 0.5 h) 87.1° 11:30 11.3 19% 65.6°
2037-01-12 Mon 20 — unknown 05:35–06:10 (good, 0.58 h) 87.1° 11:25 11.28 11% 62.1°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-12-14&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.