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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: 04-09 (54), 04-08 (52), 04-06 (51), 04-07 (51), 04-04 (50) — by astronomy; check the weather when the night is within four days.
2046-03-11astronomy score per night — click a bar for that night2046-04-09
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2046-03-11 Sun 30 — unknown 04:00–05:10 (good, 1.17 h) 71.1° 09:05 9.17 15% 85.5°
2046-03-12 Mon 30 — unknown 04:00–05:05 (good, 1.08 h) 71.1° 09:00 9.12 23% 94.6°
2046-03-13 Tue 31 — unknown 03:55–05:05 (good, 1.17 h) 71.1° 08:55 9.07 32% 103.7°
2046-03-14 Wed 32 — unknown 03:50–05:05 (good, 1.25 h) 71.1° 08:50 9.02 42% 112.7°
2046-03-15 Thu 32 — unknown 03:45–05:00 (good, 1.25 h) 71.1° 08:50 8.97 52% 121.3°
2046-03-16 Fri 33 — unknown 03:40–05:00 (good, 1.33 h) 71.1° 08:45 8.92 63% 128.9°
2046-03-17 Sat 33 — unknown 03:45–04:55 (good, 1.17 h) 71.1° 08:40 8.87 74% 134.7°
2046-03-18 Sun 34 — unknown 03:40–04:55 (good, 1.25 h) 71.1° 08:35 8.82 83% 137.6°
2046-03-19 Mon 30 — unknown 03:40–04:55 (good, 1.25 h) 71.1° 08:30 8.77 91% 136.5°
2046-03-20 Tue 30 — unknown 03:35–04:50 (good, 1.25 h) 71.1° 08:30 8.71 97% 131.5°
2046-03-21 Wed 30 — unknown 03:35–04:50 (good, 1.25 h) 71.1° 08:25 8.66 100% 123.5°
2046-03-22 Thu 29 — unknown 03:35–04:50 (good, 1.25 h) 71.1° 08:20 8.61 99% 113.8°
2046-03-23 Fri 25 — unknown 03:35–04:45 (good, 1.17 h) 71.1° 08:15 8.56 96% 103.3°
2046-03-24 Sat 24 — unknown 04:35–05:45 (good, 1.17 h) 71.1° 09:10 8.5 90% 92.5°
2046-03-25 Sun 23 — unknown 04:35–05:45 (good, 1.17 h) 71.1° 09:10 8.45 83% 82.0°
2046-03-26 Mon 23 — unknown 04:30–05:40 (good, 1.17 h) 71.1° 09:05 8.4 74% 72.1°
2046-03-27 Tue 25 — unknown 04:25–05:40 (good, 1.25 h) 71.1° 09:00 8.35 64% 63.0°
2046-03-28 Wed 27 — unknown 04:15–05:35 (good, 1.33 h) 71.1° 08:55 8.29 54% 55.0°
2046-03-29 Thu 31 — unknown 04:05–05:35 (good, 1.5 h) 71.1° 08:55 8.24 44% 48.6°
2046-03-30 Fri 37 — unknown 03:45–05:35 (good, 1.83 h) 71.1° 08:50 8.18 34% 44.2°
2046-03-31 Sat 41 — unknown 03:45–05:30 (good, 1.75 h) 71.1° 08:45 8.13 25% 42.3°
2046-04-01 Sun 45 — unknown 03:40–05:30 (good, 1.83 h) 71.1° 08:40 8.07 18% 43.1°
2046-04-02 Mon 46 — unknown 03:35–05:25 (good, 1.83 h) 71.1° 08:35 8.02 11% 46.4°
2046-04-03 Tue 48 — unknown 03:30–05:25 (good, 1.92 h) 71.1° 08:35 7.96 6% 51.7°
2046-04-04 Wed 50 — unknown 03:30–05:25 (good, 1.92 h) 71.1° 08:30 7.91 2% 58.4°
2046-04-05 Thu 50 — unknown 03:25–05:20 (good, 1.92 h) 71.1° 08:25 7.85 0% 66.1°
2046-04-06 Fri 51 — unknown 03:20–05:20 (good, 2.0 h) 71.1° 08:20 7.8 0% 74.5°
2046-04-07 Sat 51 — unknown 03:15–05:15 (good, 2.0 h) 71.1° 08:15 7.74 2% 83.4°
2046-04-08 Sun 52 — unknown 03:10–05:15 (good, 2.08 h) 71.1° 08:15 7.68 6% 92.5°
2046-04-09 Mon 54 — unknown 03:10–05:15 (good, 2.08 h) 71.1° 08:10 7.63 11% 101.7°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-03-11&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.