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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 HD 189733: 11-19 (78), 11-20 (69), 11-21 (59), 11-22 (48), 12-05 (48) — by astronomy; check the weather when the night is within four days.
2047-11-19astronomy score per night — click a bar for that night2047-12-18
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2047-11-19 Tue 78 — unknown 18:35–21:35 (good, 3.0 h) 71.2° 16:30 11.07 8% 54.6°
2047-11-20 Wed 69 — unknown 18:35–21:30 (good, 2.92 h) 71.2° 16:25 11.09 16% 46.4°
2047-11-21 Thu 59 — unknown 18:35–21:30 (good, 2.92 h) 71.1° 16:20 11.12 25% 41.0°
2047-11-22 Fri 48 — unknown 18:35–21:10 (good, 2.58 h) 71.1° 16:20 11.14 35% 39.3°
2047-11-23 Sat 40 — unknown 18:35–20:55 (good, 2.33 h) 71.2° 16:15 11.17 46% 41.3°
2047-11-24 Sun 33 — unknown 18:35–19:50 (good, 1.25 h) 71.2° 16:10 11.19 56% 46.3°
2047-11-25 Mon 28 — unknown 18:35–18:55 (good, 0.33 h) 71.2° 16:05 11.21 65% 53.1°
2047-11-26 Tue 25 — unknown 18:35–21:25 (marginal, 2.83 h) 71.1° 16:00 11.23 74% 61.1°
2047-11-27 Wed 25 — unknown 18:00–21:20 (marginal, 3.33 h) 71.1° 16:00 11.25 82% 69.7°
2047-11-28 Thu 26 — unknown 18:35–18:55 (good, 0.33 h) 71.2° 15:55 11.27 89% 78.7°
2047-11-29 Fri 29 — unknown 18:35–19:25 (good, 0.83 h) 71.2° 15:50 11.29 94% 87.8°
2047-11-30 Sat 32 — unknown 18:35–20:00 (good, 1.42 h) 71.2° 15:45 11.31 98% 96.9°
2047-12-01 Sun 37 — unknown 18:35–20:25 (good, 1.83 h) 71.1° 15:40 11.33 100% 106.0°
2047-12-02 Mon 41 — unknown 18:35–20:30 (good, 1.92 h) 71.2° 15:40 11.35 100% 114.7°
2047-12-03 Tue 44 — unknown 18:35–20:30 (good, 1.92 h) 71.2° 15:35 11.36 98% 123.0°
2047-12-04 Wed 44 — unknown 18:35–20:30 (good, 1.92 h) 71.2° 15:30 11.38 95% 130.4°
2047-12-05 Thu 48 — unknown 18:35–20:25 (good, 1.83 h) 71.1° 15:25 11.39 90% 136.3°
2047-12-06 Fri 48 — unknown 18:35–20:30 (good, 1.92 h) 71.1° 15:25 11.41 83% 140.0°
2047-12-07 Sat 46 — unknown 18:35–20:25 (good, 1.83 h) 71.2° 15:20 11.42 74% 140.6°
2047-12-08 Sun 45 — unknown 18:35–20:20 (good, 1.75 h) 71.2° 15:15 11.43 65% 137.8°
2047-12-09 Mon 44 — unknown 18:35–20:15 (good, 1.67 h) 71.2° 15:10 11.44 55% 132.1°
2047-12-10 Tue 42 — unknown 18:35–20:15 (good, 1.67 h) 71.1° 15:05 11.45 44% 124.2°
2047-12-11 Wed 40 — unknown 18:35–20:10 (good, 1.58 h) 71.1° 15:05 11.46 33% 114.7°
2047-12-12 Thu 39 — unknown 18:35–20:05 (good, 1.5 h) 71.2° 15:00 11.47 22% 104.1°
2047-12-13 Fri 38 — unknown 18:35–20:00 (good, 1.42 h) 71.2° 14:55 11.48 14% 92.8°
2047-12-14 Sat 36 — unknown 18:35–20:00 (good, 1.42 h) 71.2° 14:50 11.48 6% 81.3°
2047-12-15 Sun 34 — unknown 18:35–19:55 (good, 1.33 h) 71.1° 14:45 11.49 2% 69.9°
2047-12-16 Mon 33 — unknown 18:35–19:50 (good, 1.25 h) 71.2° 14:45 11.5 0% 59.1°
2047-12-17 Tue 32 — unknown 18:35–19:45 (good, 1.17 h) 71.2° 14:40 11.5 1% 49.8°
2047-12-18 Wed 30 — unknown 18:35–19:40 (good, 1.08 h) 71.2° 14:35 11.5 5% 42.9°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-11-19&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.