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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: 12-08 (43), 12-09 (42), 12-10 (41), 12-11 (40), 12-12 (38) — by astronomy; check the weather when the night is within four days.
2033-12-08astronomy score per night — click a bar for that night2034-01-06
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2033-12-08 Thu 43 — unknown 18:35–20:10 (good, 1.58 h) 71.1° 15:15 11.44 91% 139.8°
2033-12-09 Fri 42 — unknown 18:35–20:15 (good, 1.67 h) 71.1° 15:10 11.45 84% 142.3°
2033-12-10 Sat 41 — unknown 18:35–20:10 (good, 1.58 h) 71.1° 15:05 11.46 76% 140.8°
2033-12-11 Sun 40 — unknown 18:35–20:05 (good, 1.5 h) 71.1° 15:00 11.47 66% 136.2°
2033-12-12 Mon 38 — unknown 18:35–20:05 (good, 1.5 h) 71.1° 14:55 11.47 57% 129.5°
2033-12-13 Tue 36 — unknown 18:35–20:00 (good, 1.42 h) 71.1° 14:55 11.48 47% 121.6°
2033-12-14 Wed 35 — unknown 18:35–19:55 (good, 1.33 h) 71.1° 14:50 11.49 38% 113.0°
2033-12-15 Thu 34 — unknown 18:35–19:50 (good, 1.25 h) 71.1° 14:45 11.49 29% 103.9°
2033-12-16 Fri 32 — unknown 18:35–19:50 (good, 1.25 h) 71.1° 14:40 11.5 21% 94.7°
2033-12-17 Sat 31 — unknown 18:35–19:45 (good, 1.17 h) 71.1° 14:35 11.5 14% 85.2°
2033-12-18 Sun 29 — unknown 18:35–19:40 (good, 1.08 h) 71.1° 14:35 11.5 8% 75.8°
2033-12-19 Mon 28 — unknown 18:35–19:35 (good, 1.0 h) 71.1° 14:30 11.51 4% 66.5°
2033-12-20 Tue 27 — unknown 18:35–19:30 (good, 0.92 h) 71.1° 14:25 11.51 1% 57.6°
2033-12-21 Wed 25 — unknown 18:35–19:30 (good, 0.92 h) 71.1° 14:20 11.51 0% 49.4°
2033-12-22 Thu 23 — unknown 18:35–19:25 (good, 0.83 h) 71.1° 14:20 11.51 2% 42.8°
2033-12-23 Fri 20 — unknown 18:40–19:20 (good, 0.67 h) 71.1° 14:15 11.5 5% 38.6°
2033-12-24 Sat 18 — unknown 18:40–19:10 (good, 0.5 h) 71.1° 14:10 11.5 11% 38.1°
2033-12-25 Sun 16 — unknown 18:40–19:05 (good, 0.42 h) 71.1° 14:05 11.5 18% 41.4°
2033-12-26 Mon 13 — unknown 18:40–18:55 (good, 0.25 h) 71.1° 14:00 11.49 28% 47.9°
2033-12-27 Tue 10 — unknown 18:40–18:45 (good, 0.08 h) 71.1° 14:00 11.49 38% 56.6°
2033-12-28 Wed 8 — unknown 18:40–19:30 (marginal, 0.83 h) 71.1° 13:55 11.48 49% 66.6°
2033-12-29 Thu 7 — unknown 18:40–19:25 (marginal, 0.75 h) 71.1° 13:50 11.48 60% 77.4°
2033-12-30 Fri 6 — unknown 18:40–19:20 (marginal, 0.67 h) 71.1° 13:45 11.47 71% 88.6°
2033-12-31 Sat 5 — unknown 18:45–19:15 (marginal, 0.5 h) 71.1° 13:40 11.46 81% 99.9°
2034-01-01 Sun 5 — unknown 18:45–19:10 (marginal, 0.42 h) 71.1° 13:40 11.45 89% 110.9°
2034-01-02 Mon 5 — unknown 18:45–19:10 (marginal, 0.42 h) 71.1° 13:35 11.44 95% 121.4°
2034-01-03 Tue 4 — unknown 18:45–19:05 (marginal, 0.33 h) 71.1° 13:30 11.43 99% 130.5°
2034-01-04 Wed 3 — unknown 18:45–19:00 (marginal, 0.25 h) 71.1° 13:25 11.41 100% 137.6°
2034-01-05 Thu 3 — unknown 18:45–18:55 (marginal, 0.17 h) 71.1° 13:25 11.4 98% 141.6°
2034-01-06 Fri 2 — unknown 18:15–18:25 (marginal, 0.17 h) 71.1° 13:20 11.39 95% 141.7°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-12-08&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.