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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: 02-25 (29), 02-26 (24), 02-27 (18), 03-07 (15), 02-28 (14) — by astronomy; check the weather when the night is within four days.
2031-02-25astronomy score per night — click a bar for that night2031-03-26
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2031-02-25 Tue 29 — unknown 19:40–21:00 (good, 1.33 h) 79.1° 15:35 9.83 20% 16.9°
2031-02-26 Wed 24 — unknown 19:40–20:45 (good, 1.08 h) 79.1° 15:30 9.79 29% 20.4°
2031-02-27 Thu 18 — unknown 19:45–20:25 (good, 0.67 h) 79.1° 15:30 9.75 38% 28.9°
2031-02-28 Fri 14 — unknown 19:45–21:20 (marginal, 1.58 h) 79.1° 15:25 9.7 48% 39.2°
2031-03-01 Sat 12 — unknown 19:45–21:15 (marginal, 1.5 h) 79.1° 15:20 9.66 57% 50.0°
2031-03-02 Sun 11 — unknown 19:45–21:05 (marginal, 1.33 h) 79.1° 15:15 9.61 66% 61.0°
2031-03-03 Mon 11 — unknown 19:50–21:05 (marginal, 1.25 h) 79.1° 15:10 9.56 75% 72.3°
2031-03-04 Tue 11 — unknown 19:50–21:00 (marginal, 1.17 h) 79.1° 15:10 9.52 83% 83.7°
2031-03-05 Wed 12 — unknown 19:50–19:55 (good, 0.08 h) 79.1° 15:05 9.47 89% 95.3°
2031-03-06 Thu 14 — unknown 19:50–20:10 (good, 0.33 h) 79.1° 15:00 9.42 95% 107.1°
2031-03-07 Fri 15 — unknown 19:55–20:15 (good, 0.33 h) 79.1° 14:55 9.38 98% 119.0°
2031-03-08 Sat 14 — unknown 19:55–20:15 (good, 0.33 h) 79.1° 14:55 9.33 100% 131.0°
2031-03-09 Sun 13 — unknown 19:55–20:10 (good, 0.25 h) 79.1° 14:50 9.28 99% 142.8°
2031-03-10 Mon 14 — unknown 19:55–20:10 (good, 0.25 h) 79.1° 14:45 9.23 96% 153.8°
2031-03-11 Tue 11 — unknown 20:00–20:15 (good, 0.25 h) 79.1° 14:40 9.18 91% 161.8°
2031-03-12 Wed 10 — unknown 20:00–20:10 (good, 0.17 h) 79.1° 14:35 9.14 84% 161.6°
2031-03-13 Thu 9 — unknown 20:00–20:05 (good, 0.08 h) 79.1° 14:35 9.09 75% 153.3°
2031-03-14 Fri 7 — unknown 19:30–20:30 (marginal, 1.0 h) 79.1° 14:30 9.04 65% 141.6°
2031-03-15 Sat 6 — unknown 20:05–20:25 (marginal, 0.33 h) 79.1° 14:25 8.99 54% 128.9°
2031-03-16 Sun 5 — unknown 19:30–19:55 (marginal, 0.42 h) 79.1° 14:20 8.94 42% 115.6°
2031-03-17 Mon 4 — unknown 20:05–20:20 (marginal, 0.25 h) 79.1° 14:15 8.89 31% 102.1°
2031-03-18 Tue 3 — unknown 20:05–20:15 (marginal, 0.17 h) 79.1° 14:15 8.84 21% 88.5°
2031-03-19 Wed 2 — unknown 20:05–20:10 (marginal, 0.08 h) 79.1° 14:10 8.78 13% 75.0°
2031-03-20 Thu 1 — unknown 19:35–19:40 (marginal, 0.08 h) 79.1° 14:05 8.73 6% 61.7°
2031-03-21 Fri 1 — unknown — 79.1° 14:00 8.68 2% 48.7°
2031-03-22 Sat 1 — unknown — 79.1° 13:55 8.63 0% 36.3°
2031-03-23 Sun 1 — unknown — 79.1° 13:55 8.58 1% 25.4°
2031-03-24 Mon 0 — unknown — 79.1° 13:50 8.52 4% 18.1°
2031-03-25 Tue 0 — unknown — 79.1° 13:45 8.47 8% 18.3°
2031-03-26 Wed 0 — unknown — 79.1° 13:40 8.42 15% 25.6°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2031-02-25&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.