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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: 06-27 (23), 06-26 (22), 06-25 (20), 06-24 (18), 06-23 (17) — by astronomy; check the weather when the night is within four days.
2042-05-29astronomy score per night — click a bar for that night2042-06-27
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2042-05-29 Thu 0 — unknown — 79.2° 10:25 4.91 78% 151.6°
2042-05-30 Fri 1 — unknown — 79.2° 10:20 4.87 86% 158.9°
2042-05-31 Sat 1 — unknown — 79.2° 10:20 4.83 92% 161.2°
2042-06-01 Sun 1 — unknown — 79.2° 10:15 4.79 96% 156.7°
2042-06-02 Mon 1 — unknown — 79.2° 10:10 4.76 99% 147.8°
2042-06-03 Tue 1 — unknown — 79.2° 10:05 4.72 100% 137.1°
2042-06-04 Wed 1 — unknown — 79.2° 10:00 4.69 99% 125.5°
2042-06-05 Thu 1 — unknown — 79.2° 10:00 4.66 95% 113.4°
2042-06-06 Fri 1 — unknown — 79.2° 09:55 4.63 90% 100.8°
2042-06-07 Sat 1 — unknown — 79.2° 09:50 4.6 82% 88.1°
2042-06-08 Sun 1 — unknown — 79.2° 09:45 4.58 73% 75.1°
2042-06-09 Mon 1 — unknown — 79.2° 09:40 4.55 62% 62.1°
2042-06-10 Tue 2 — unknown — 79.2° 09:40 4.53 51% 49.2°
2042-06-11 Wed 2 — unknown — 79.2° 09:35 4.51 40% 36.7°
2042-06-12 Thu 3 — unknown 04:20–04:30 (marginal, 0.17 h) 79.2° 09:30 4.49 29% 25.6°
2042-06-13 Fri 4 — unknown 04:05–04:30 (marginal, 0.42 h) 79.2° 09:25 4.48 19% 18.9°
2042-06-14 Sat 6 — unknown 04:00–04:30 (marginal, 0.5 h) 79.2° 09:25 4.46 11% 21.4°
2042-06-15 Sun 7 — unknown 03:50–04:30 (marginal, 0.67 h) 79.2° 09:20 4.45 5% 30.9°
2042-06-16 Mon 7 — unknown 03:45–04:30 (marginal, 0.75 h) 79.2° 09:15 4.44 1% 42.9°
2042-06-17 Tue 8 — unknown 03:45–04:30 (marginal, 0.75 h) 79.2° 09:10 4.43 0% 55.6°
2042-06-18 Wed 10 — unknown 03:10–04:30 (marginal, 1.33 h) 79.2° 09:05 4.43 2% 68.3°
2042-06-19 Thu 11 — unknown 03:35–03:40 (good, 0.08 h) 79.2° 09:05 4.42 6% 80.9°
2042-06-20 Fri 12 — unknown 03:30–03:40 (good, 0.17 h) 79.2° 09:00 4.42 11% 93.2°
2042-06-21 Sat 13 — unknown 03:30–03:40 (good, 0.17 h) 79.2° 08:55 4.42 18% 105.2°
2042-06-22 Sun 15 — unknown 03:25–03:40 (good, 0.25 h) 79.2° 08:50 4.42 26% 116.9°
2042-06-23 Mon 17 — unknown 03:20–03:40 (good, 0.33 h) 79.2° 08:45 4.43 36% 128.1°
2042-06-24 Tue 18 — unknown 03:15–03:40 (good, 0.42 h) 79.2° 08:45 4.44 45% 138.8°
2042-06-25 Wed 20 — unknown 03:10–03:40 (good, 0.5 h) 79.2° 08:40 4.44 54% 148.8°
2042-06-26 Thu 22 — unknown 03:10–03:40 (good, 0.5 h) 79.2° 08:35 4.46 64% 157.1°
2042-06-27 Fri 23 — unknown 03:05–03:40 (good, 0.58 h) 79.2° 08:30 4.47 72% 161.4°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-05-29&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.