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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 Seven Sisters: 07-26 (8), 07-21 (7), 07-24 (7), 07-25 (7), 07-19 (6) — by astronomy; check the weather when the night is within four days.
2035-06-27astronomy score per night — click a bar for that night2035-07-26
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2035-06-27 Wed 0 — unknown — 72.5° 10:45 4.47 59% 64.1°
2035-06-28 Thu 0 — unknown — 72.5° 10:40 4.48 48% 51.2°
2035-06-29 Fri 0 — unknown — 72.5° 10:35 4.5 38% 38.1°
2035-06-30 Sat 0 — unknown — 72.5° 10:35 4.51 27% 24.9°
2035-07-01 Sun 0 — unknown — 72.5° 10:30 4.53 17% 12.7°
2035-07-02 Mon 0 — unknown — 72.5° 10:25 4.56 9% 10.9°
2035-07-03 Tue 0 — unknown — 72.5° 10:20 4.58 4% 22.8°
2035-07-04 Wed 0 — unknown — 72.5° 10:15 4.61 0% 37.1°
2035-07-05 Thu 0 — unknown — 72.5° 10:15 4.63 0% 51.9°
2035-07-06 Fri 0 — unknown — 72.5° 10:10 4.66 4% 66.7°
2035-07-07 Sat 1 — unknown — 72.5° 10:05 4.69 9% 81.2°
2035-07-08 Sun 1 — unknown — 72.5° 10:00 4.73 17% 95.3°
2035-07-09 Mon 1 — unknown — 72.5° 09:55 4.76 26% 108.9°
2035-07-10 Tue 1 — unknown — 72.5° 09:55 4.79 36% 122.0°
2035-07-11 Wed 1 — unknown — 72.5° 09:50 4.83 46% 134.7°
2035-07-12 Thu 2 — unknown 04:40–04:45 (marginal, 0.08 h) 72.5° 09:45 4.87 56% 146.8°
2035-07-13 Fri 2 — unknown 04:35–04:45 (marginal, 0.17 h) 72.5° 09:40 4.91 66% 158.3°
2035-07-14 Sat 2 — unknown 04:30–04:45 (marginal, 0.25 h) 72.5° 09:40 4.95 75% 168.0°
2035-07-15 Sun 3 — unknown 04:30–04:50 (marginal, 0.33 h) 72.5° 09:35 4.99 82% 169.8°
2035-07-16 Mon 4 — unknown 04:25–04:50 (marginal, 0.42 h) 72.5° 09:30 5.03 89% 161.5°
2035-07-17 Tue 4 — unknown 04:20–04:50 (marginal, 0.5 h) 72.5° 09:25 5.08 94% 150.7°
2035-07-18 Wed 5 — unknown 04:25–04:50 (marginal, 0.42 h) 72.5° 09:20 5.12 98% 139.3°
2035-07-19 Thu 6 — unknown 04:20–04:50 (marginal, 0.5 h) 72.5° 09:20 5.17 100% 127.7°
2035-07-20 Fri 6 — unknown 04:20–04:55 (marginal, 0.58 h) 72.5° 09:15 5.22 100% 115.9°
2035-07-21 Sat 7 — unknown 03:35–04:10 (marginal, 0.58 h) 72.5° 09:10 5.26 98% 104.0°
2035-07-22 Sun 6 — unknown 03:35–04:10 (marginal, 0.58 h) 72.5° 09:05 5.31 94% 91.9°
2035-07-23 Mon 6 — unknown 03:35–04:10 (marginal, 0.58 h) 72.5° 09:00 5.36 89% 79.6°
2035-07-24 Tue 7 — unknown 03:35–04:15 (marginal, 0.67 h) 72.5° 09:00 5.41 82% 67.1°
2035-07-25 Wed 7 — unknown 03:30–04:15 (marginal, 0.75 h) 72.5° 08:55 5.46 73% 54.4°
2035-07-26 Thu 8 — unknown 03:25–04:15 (marginal, 0.83 h) 72.5° 08:50 5.52 63% 41.6°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-06-27&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.