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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: 07-29 (92), 07-28 (91), 07-27 (89), 07-26 (84), 07-25 (82) — by astronomy; check the weather when the night is within four days.
2041-06-30astronomy score per night — click a bar for that night2041-07-29
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2041-06-30 Sun 29 — unknown 02:50–03:45 (good, 0.92 h) 79.2° 08:20 4.52 6% 92.2°
2041-07-01 Mon 30 — unknown 02:45–03:45 (good, 1.0 h) 79.2° 08:15 4.55 11% 103.4°
2041-07-02 Tue 31 — unknown 02:45–03:45 (good, 1.0 h) 79.2° 08:10 4.57 18% 114.5°
2041-07-03 Wed 33 — unknown 02:40–03:45 (good, 1.08 h) 79.2° 08:05 4.59 26% 125.3°
2041-07-04 Thu 35 — unknown 02:35–03:45 (good, 1.17 h) 79.2° 08:05 4.62 34% 135.9°
2041-07-05 Fri 37 — unknown 02:30–03:50 (good, 1.33 h) 79.2° 08:00 4.65 44% 145.8°
2041-07-06 Sat 39 — unknown 02:30–03:50 (good, 1.33 h) 79.2° 07:55 4.68 53% 154.4°
2041-07-07 Sun 40 — unknown 02:25–03:50 (good, 1.42 h) 79.2° 07:50 4.71 63% 159.5°
2041-07-08 Mon 42 — unknown 02:20–03:50 (good, 1.5 h) 79.2° 07:45 4.74 73% 158.0°
2041-07-09 Tue 43 — unknown 02:20–03:50 (good, 1.5 h) 79.2° 07:45 4.78 82% 150.4°
2041-07-10 Wed 45 — unknown 02:20–03:55 (good, 1.58 h) 79.2° 07:40 4.81 89% 139.6°
2041-07-11 Thu 45 — unknown 02:15–03:55 (good, 1.67 h) 79.2° 07:35 4.85 95% 127.3°
2041-07-12 Fri 40 — unknown 02:15–03:55 (good, 1.67 h) 79.2° 07:30 4.89 99% 114.1°
2041-07-13 Sat 34 — unknown 02:20–03:55 (good, 1.58 h) 79.2° 07:30 4.93 100% 100.4°
2041-07-14 Sun 29 — unknown 02:50–04:00 (good, 1.17 h) 79.2° 07:25 4.97 98% 86.4°
2041-07-15 Mon 25 — unknown 03:55–04:00 (good, 0.08 h) 79.2° 07:20 5.01 93% 72.4°
2041-07-16 Tue 22 — unknown 01:30–04:00 (marginal, 2.5 h) 79.2° 07:15 5.06 86% 58.6°
2041-07-17 Wed 21 — unknown 01:25–04:05 (marginal, 2.67 h) 79.2° 07:10 5.1 77% 45.5°
2041-07-18 Thu 23 — unknown 01:15–04:05 (marginal, 2.83 h) 79.2° 07:10 5.15 66% 33.4°
2041-07-19 Fri 29 — unknown 03:30–04:05 (good, 0.58 h) 79.2° 07:05 5.19 55% 23.9°
2041-07-20 Sat 38 — unknown 01:55–04:05 (good, 2.17 h) 79.2° 07:00 5.24 44% 20.1°
2041-07-21 Sun 48 — unknown 01:45–04:10 (good, 2.42 h) 79.2° 06:55 5.29 34% 24.2°
2041-07-22 Mon 59 — unknown 01:25–04:10 (good, 2.75 h) 79.2° 06:50 5.34 24% 33.1°
2041-07-23 Tue 69 — unknown 01:20–04:10 (good, 2.83 h) 79.2° 06:50 5.39 16% 43.8°
2041-07-24 Wed 76 — unknown 01:15–04:15 (good, 3.0 h) 79.2° 06:45 5.44 9% 55.0°
2041-07-25 Thu 82 — unknown 01:15–04:15 (good, 3.0 h) 79.2° 06:40 5.49 4% 66.4°
2041-07-26 Fri 84 — unknown 01:10–04:15 (good, 3.08 h) 79.2° 06:35 5.54 1% 77.8°
2041-07-27 Sat 89 — unknown 01:05–04:20 (good, 3.25 h) 79.2° 06:35 5.6 0% 89.1°
2041-07-28 Sun 91 — unknown 01:00–04:20 (good, 3.33 h) 79.2° 06:30 5.65 1% 100.4°
2041-07-29 Mon 92 — unknown 00:55–04:20 (good, 3.42 h) 79.2° 06:25 5.7 3% 111.5°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-06-30&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.