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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: 06-18 (8), 06-16 (7), 06-17 (7), 06-14 (6), 06-15 (6) — by astronomy; check the weather when the night is within four days.
2035-05-20astronomy score per night — click a bar for that night2035-06-18
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2035-05-20 Sun 0 — unknown — 79.1° 11:00 5.33 98% 153.1°
2035-05-21 Mon 0 — unknown — 79.1° 11:00 5.28 100% 145.7°
2035-05-22 Tue 0 — unknown — 79.1° 10:55 5.23 99% 136.5°
2035-05-23 Wed 0 — unknown — 79.1° 10:50 5.18 97% 126.4°
2035-05-24 Thu 0 — unknown — 79.1° 10:45 5.14 93% 116.0°
2035-05-25 Fri 0 — unknown — 79.1° 10:40 5.09 88% 105.3°
2035-05-26 Sat 0 — unknown — 79.1° 10:40 5.05 81% 94.4°
2035-05-27 Sun 0 — unknown — 79.1° 10:35 5.0 73% 83.3°
2035-05-28 Mon 0 — unknown — 79.1° 10:30 4.96 64% 72.2°
2035-05-29 Tue 0 — unknown — 79.1° 10:25 4.92 54% 61.0°
2035-05-30 Wed 0 — unknown — 79.1° 10:20 4.88 44% 49.9°
2035-05-31 Thu 1 — unknown — 79.1° 10:20 4.84 33% 39.1°
2035-06-01 Fri 1 — unknown — 79.1° 10:15 4.8 24% 29.6°
2035-06-02 Sat 1 — unknown — 79.1° 10:10 4.77 15% 23.8°
2035-06-03 Sun 1 — unknown — 79.1° 10:05 4.73 7% 25.3°
2035-06-04 Mon 1 — unknown — 79.1° 10:05 4.7 2% 33.6°
2035-06-05 Tue 2 — unknown 04:30–04:35 (marginal, 0.08 h) 79.1° 10:00 4.67 0% 45.3°
2035-06-06 Wed 2 — unknown 04:30–04:35 (marginal, 0.08 h) 79.1° 09:55 4.64 1% 58.5°
2035-06-07 Thu 2 — unknown 04:25–04:30 (marginal, 0.08 h) 79.1° 09:50 4.61 5% 72.1°
2035-06-08 Fri 2 — unknown 04:20–04:30 (marginal, 0.17 h) 79.1° 09:45 4.59 12% 85.7°
2035-06-09 Sat 3 — unknown 04:15–04:30 (marginal, 0.25 h) 79.1° 09:45 4.56 20% 99.1°
2035-06-10 Sun 3 — unknown 04:10–04:30 (marginal, 0.33 h) 79.1° 09:40 4.54 30% 112.0°
2035-06-11 Mon 3 — unknown 04:10–04:30 (marginal, 0.33 h) 79.1° 09:35 4.52 40% 124.2°
2035-06-12 Tue 4 — unknown 04:05–04:30 (marginal, 0.42 h) 79.1° 09:30 4.5 51% 135.5°
2035-06-13 Wed 5 — unknown 04:00–04:30 (marginal, 0.5 h) 79.1° 09:25 4.48 61% 145.5°
2035-06-14 Thu 6 — unknown 03:55–04:30 (marginal, 0.58 h) 79.1° 09:25 4.47 71% 153.1°
2035-06-15 Fri 6 — unknown 03:50–04:30 (marginal, 0.67 h) 79.1° 09:20 4.46 79% 156.5°
2035-06-16 Sat 7 — unknown 03:50–04:30 (marginal, 0.67 h) 79.1° 09:15 4.44 87% 154.3°
2035-06-17 Sun 7 — unknown 03:50–04:30 (marginal, 0.67 h) 79.1° 09:10 4.44 92% 147.7°
2035-06-18 Mon 8 — unknown 03:50–04:30 (marginal, 0.67 h) 79.1° 09:10 4.43 97% 138.8°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-05-20&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.