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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 North America Nebula: 06-10 (100), 06-11 (100), 06-12 (100), 06-13 (100), 06-14 (100) — by astronomy; check the weather when the night is within four days.
2026-06-05astronomy score per night — click a bar for that night2026-07-04
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2026-06-05 Fri 86 78 67 02:00–03:00 (good, 1.0 h) 87.2° 05:25 4.66 74% 61.8°
2026-06-06 Sat 90 72 65 23:25–01:00 (good, 1.58 h) 87.2° 05:20 4.63 65% 58.5°
2026-06-07 Sun 94 95 89 23:15–03:40 (good, 4.42 h) 87.3° 05:15 4.61 55% 56.8°
2026-06-08 Mon 96 0 0 — 87.3° 05:10 4.58 45% 56.9°
2026-06-09 Tue 99 98 97 23:05–03:40 (good, 4.58 h) 87.2° 05:05 4.56 34% 59.0°
2026-06-10 Wed 100 95 95 23:05–03:40 (good, 4.58 h) 87.2° 05:05 4.53 24% 63.0°
2026-06-11 Thu 100 48 48 23:10–02:00 (good, 2.83 h) 87.3° 05:00 4.51 15% 68.8°
2026-06-12 Fri 100 0 0 — 87.3° 04:55 4.49 7% 75.9°
2026-06-13 Sat 100 94 94 23:10–03:40 (good, 4.5 h) 87.2° 04:50 4.48 2% 83.8°
2026-06-14 Sun 100 91 91 23:10–03:40 (good, 4.5 h) 87.2° 04:45 4.46 0% 92.2°
2026-06-15 Mon 100 64 64 02:00–03:40 (good, 1.67 h) 87.2° 04:45 4.45 1% 100.5°
2026-06-16 Tue 100 0 0 — 87.3° 04:40 4.44 5% 108.1°
2026-06-17 Wed 100 35 35 03:00–03:40 (good, 0.67 h) 87.3° 04:35 4.43 12% 114.6°
2026-06-18 Thu 100 74 74 23:10–03:40 (good, 4.5 h) 87.2° 04:30 4.43 20% 119.6°
2026-06-19 Fri 100 92 92 23:10–03:40 (good, 4.5 h) 87.2° 04:30 4.42 30% 122.6°
2026-06-20 Sat 100 98 98 23:15–03:40 (good, 4.42 h) 87.2° 04:25 4.42 40% 123.5°
2026-06-21 Sun 100 99 99 23:15–03:40 (good, 4.42 h) 87.3° 04:20 4.42 50% 122.5°
2026-06-22 Mon 100 89 89 23:15–03:40 (good, 4.42 h) 87.3° 04:15 4.42 60% 119.7°
2026-06-23 Tue 100 59 59 01:00–03:40 (good, 2.67 h) 87.2° 04:10 4.43 70% 115.5°
2026-06-24 Wed 100 86 86 23:15–03:40 (good, 4.42 h) 87.2° 04:10 4.43 78% 110.4°
2026-06-25 Thu 100 89 89 23:15–03:40 (good, 4.42 h) 87.3° 04:05 4.44 86% 104.6°
2026-06-26 Fri 100 95 95 23:15–03:40 (good, 4.42 h) 87.3° 04:00 4.45 92% 98.4°
2026-06-27 Sat 82 67 55 23:20–03:00 (good, 3.67 h) 87.3° 03:55 4.47 96% 91.9°
2026-06-28 Sun 77 100 77 23:15–03:40 (good, 4.42 h) 87.2° 03:50 4.48 99% 85.4°
2026-06-29 Mon 69 89 62 02:00–03:40 (good, 1.67 h) 87.2° 03:50 4.5 100% 79.0°
2026-06-30 Tue 62 96 60 23:50–03:45 (good, 3.92 h) 87.3° 03:45 4.52 99% 72.9°
2026-07-01 Wed 60 27 16 23:10–00:00 (marginal, 0.83 h) 87.3° 03:40 4.54 96% 67.3°
2026-07-02 Thu 60 74 45 23:10–03:45 (marginal, 4.58 h) 87.2° 03:35 4.56 92% 62.6°
2026-07-03 Fri 84 32 27 02:00–03:00 (marginal, 1.0 h) 87.2° 03:35 4.58 86% 59.0°
2026-07-04 Sat 92 72 67 01:00–02:00 (good, 1.0 h) 87.2° 03:30 4.61 78% 56.8°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-06-05&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.