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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 Triangulum Pinwheel: 07-16 (41), 07-15 (34), 07-03 (32), 07-01 (31), 07-02 (31) — by astronomy; check the weather when the night is within four days.
2028-06-17astronomy score per night — click a bar for that night2028-07-16
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2028-06-17 Sat 7 — unknown 03:10–03:40 (marginal, 0.5 h) 79.1° 09:10 4.43 25% 15.1°
2028-06-18 Sun 9 — unknown 03:45–04:30 (marginal, 0.75 h) 79.1° 09:05 4.43 16% 16.0°
2028-06-19 Mon 11 — unknown 03:35–03:40 (good, 0.08 h) 79.1° 09:00 4.42 10% 24.6°
2028-06-20 Tue 13 — unknown 03:30–03:40 (good, 0.17 h) 79.1° 08:55 4.42 4% 36.1°
2028-06-21 Wed 14 — unknown 03:25–03:40 (good, 0.25 h) 79.1° 08:55 4.42 1% 48.8°
2028-06-22 Thu 15 — unknown 03:20–03:40 (good, 0.33 h) 79.1° 08:50 4.43 0% 62.0°
2028-06-23 Fri 17 — unknown 03:20–03:40 (good, 0.33 h) 79.1° 08:45 4.43 2% 75.7°
2028-06-24 Sat 19 — unknown 03:15–03:40 (good, 0.42 h) 79.1° 08:40 4.44 6% 89.7°
2028-06-25 Sun 21 — unknown 03:10–03:40 (good, 0.5 h) 79.1° 08:35 4.45 13% 103.7°
2028-06-26 Mon 23 — unknown 03:05–03:40 (good, 0.58 h) 79.1° 08:35 4.46 22% 117.7°
2028-06-27 Tue 24 — unknown 03:00–03:40 (good, 0.67 h) 79.1° 08:30 4.47 32% 131.4°
2028-06-28 Wed 25 — unknown 03:00–03:40 (good, 0.67 h) 79.1° 08:25 4.49 43% 144.6°
2028-06-29 Thu 28 — unknown 02:55–03:45 (good, 0.83 h) 79.1° 08:20 4.51 55% 156.7°
2028-06-30 Fri 29 — unknown 02:50–03:45 (good, 0.92 h) 79.1° 08:15 4.53 66% 165.1°
2028-07-01 Sat 31 — unknown 02:45–03:45 (good, 1.0 h) 79.1° 08:15 4.55 76% 163.3°
2028-07-02 Sun 31 — unknown 02:40–03:45 (good, 1.08 h) 79.1° 08:10 4.57 85% 153.6°
2028-07-03 Mon 32 — unknown 02:45–03:45 (good, 1.0 h) 79.1° 08:05 4.6 92% 141.9°
2028-07-04 Tue 30 — unknown 02:45–03:45 (good, 1.0 h) 79.1° 08:00 4.62 96% 129.6°
2028-07-05 Wed 30 — unknown 02:40–03:50 (good, 1.17 h) 79.1° 08:00 4.65 99% 117.3°
2028-07-06 Thu 26 — unknown 02:45–03:50 (good, 1.08 h) 79.1° 07:55 4.68 100% 105.1°
2028-07-07 Fri 23 — unknown 02:55–03:50 (good, 0.92 h) 79.1° 07:50 4.71 99% 93.0°
2028-07-08 Sat 20 — unknown 01:55–04:40 (marginal, 2.75 h) 79.1° 07:45 4.75 95% 81.2°
2028-07-09 Sun 18 — unknown 01:55–03:55 (marginal, 2.0 h) 79.1° 07:40 4.78 90% 69.5°
2028-07-10 Mon 16 — unknown 01:55–03:55 (marginal, 2.0 h) 79.1° 07:40 4.82 84% 58.0°
2028-07-11 Tue 16 — unknown 01:50–03:55 (marginal, 2.08 h) 79.1° 07:35 4.86 77% 46.7°
2028-07-12 Wed 17 — unknown 01:45–03:55 (marginal, 2.17 h) 79.1° 07:30 4.9 68% 35.8°
2028-07-13 Thu 20 — unknown 01:35–04:00 (marginal, 2.42 h) 79.1° 07:25 4.94 59% 25.4°
2028-07-14 Fri 27 — unknown 03:05–04:00 (good, 0.92 h) 79.1° 07:20 4.98 49% 16.9°
2028-07-15 Sat 34 — unknown 02:10–04:00 (good, 1.83 h) 79.1° 07:20 5.02 40% 14.5°
2028-07-16 Sun 41 — unknown 02:00–04:00 (good, 2.0 h) 79.1° 07:15 5.06 30% 20.9°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-06-17&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.