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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: 06-14 (100), 06-15 (100), 06-16 (100), 06-17 (100), 06-18 (100) — by astronomy; check the weather when the night is within four days.
2025-06-14astronomy score per night — click a bar for that night2025-07-13
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2025-06-14 Sat 100 37 37 02:00–02:45 (good, 0.75 h) 87.1° 02:25 4.46 87% 67.3°
2025-06-15 Sun 100 81 81 23:10–01:00 (good, 1.83 h) 87.1° 02:20 4.45 79% 69.5°
2025-06-16 Mon 100 97 97 23:10–03:40 (good, 4.5 h) 87.1° 02:15 4.44 70% 72.8°
2025-06-17 Tue 100 98 98 23:10–03:40 (good, 4.5 h) 87.1° 02:15 4.43 60% 77.0°
2025-06-18 Wed 100 97 97 23:10–03:40 (good, 4.5 h) 87.1° 02:10 4.43 49% 82.0°
2025-06-19 Thu 100 96 96 23:10–03:40 (good, 4.5 h) 87.1° 02:05 4.42 37% 87.6°
2025-06-20 Fri 100 91 91 23:15–03:40 (good, 4.42 h) 87.1° 02:00 4.42 26% 93.3°
2025-06-21 Sat 100 82 82 00:00–03:40 (good, 3.67 h) 87.1° 01:55 4.42 17% 99.0°
2025-06-22 Sun 100 100 100 23:15–03:40 (good, 4.42 h) 87.1° 01:55 4.42 9% 104.2°
2025-06-23 Mon 100 100 100 23:15–03:40 (good, 4.42 h) 87.1° 01:50 4.43 3% 108.6°
2025-06-24 Tue 100 100 100 23:15–03:40 (good, 4.42 h) 87.1° 01:45 4.44 1% 111.8°
2025-06-25 Wed 100 100 100 23:15–03:40 (good, 4.42 h) 87.1° 01:40 4.45 0% 113.5°
2025-06-26 Thu 100 100 100 23:15–03:40 (good, 4.42 h) 87.1° 01:40 4.46 3% 113.6°
2025-06-27 Fri 100 78 78 23:15–03:40 (good, 4.42 h) 87.1° 01:35 4.47 8% 112.3°
2025-06-28 Sat 100 37 37 03:00–03:40 (good, 0.67 h) 87.1° 01:30 4.48 15% 109.8°
2025-06-29 Sun 100 100 100 23:10–03:40 (good, 4.5 h) 87.1° 01:25 4.5 23% 106.3°
2025-06-30 Mon 100 94 94 23:10–03:45 (good, 4.58 h) 87.1° 01:20 4.52 32% 102.2°
2025-07-01 Tue 100 87 87 00:00–03:45 (good, 3.75 h) 87.1° 01:20 4.54 42% 97.7°
2025-07-02 Wed 100 100 100 23:10–03:45 (good, 4.58 h) 87.1° 01:15 4.56 51% 92.9°
2025-07-03 Thu 100 100 100 23:10–03:45 (good, 4.58 h) 87.1° 01:10 4.59 61% 88.1°
2025-07-04 Fri 100 100 100 23:10–03:45 (good, 4.58 h) 87.1° 01:05 4.62 70% 83.4°
2025-07-05 Sat 100 100 100 23:10–03:50 (good, 4.67 h) 87.1° 01:00 4.64 78% 79.0°
2025-07-06 Sun 100 99 99 23:10–03:50 (good, 4.67 h) 87.1° 01:00 4.67 85% 74.9°
2025-07-07 Mon 100 99 99 23:10–03:50 (good, 4.67 h) 87.1° 00:55 4.7 91% 71.4°
2025-07-08 Tue 73 100 73 23:05–03:50 (good, 4.75 h) 87.1° 00:50 4.74 96% 68.7°
2025-07-09 Wed 66 99 65 23:05–03:50 (good, 4.75 h) 87.1° 00:45 4.77 99% 66.9°
2025-07-10 Thu 63 81 51 00:00–01:00 (good, 1.0 h) 87.1° 00:45 4.81 100% 66.2°
2025-07-11 Fri 65 40 26 02:00–03:55 (marginal, 1.92 h) 87.1° 00:40 4.85 99% 66.8°
2025-07-12 Sat 71 86 61 02:00–03:55 (good, 1.92 h) 87.1° 00:35 4.88 95% 68.7°
2025-07-13 Sun 77 46 35 00:00–01:00 (marginal, 1.0 h) 87.1° 00:30 4.92 90% 71.7°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2025-06-14&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.