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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: 02-24 (38), 02-25 (37), 02-26 (36), 02-27 (33), 02-28 (31) — by astronomy; check the weather when the night is within four days.
2027-02-24astronomy score per night — click a bar for that night2027-03-25
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2027-02-24 Wed 38 — unknown 19:40–21:10 (good, 1.5 h) 79.1° 15:40 9.88 81% 164.6°
2027-02-25 Thu 37 — unknown 19:40–21:10 (good, 1.5 h) 79.1° 15:35 9.84 72% 164.0°
2027-02-26 Fri 36 — unknown 19:40–21:05 (good, 1.42 h) 79.1° 15:30 9.79 62% 155.6°
2027-02-27 Sat 33 — unknown 19:45–21:00 (good, 1.25 h) 79.1° 15:30 9.75 53% 145.1°
2027-02-28 Sun 31 — unknown 19:45–20:55 (good, 1.17 h) 79.1° 15:25 9.7 43% 133.9°
2027-03-01 Mon 29 — unknown 19:45–20:50 (good, 1.08 h) 79.1° 15:20 9.66 34% 122.7°
2027-03-02 Tue 28 — unknown 19:45–20:50 (good, 1.08 h) 79.1° 15:15 9.61 25% 111.3°
2027-03-03 Wed 26 — unknown 19:50–20:45 (good, 0.92 h) 79.1° 15:10 9.57 18% 99.9°
2027-03-04 Thu 24 — unknown 19:50–20:40 (good, 0.83 h) 79.1° 15:10 9.52 11% 88.4°
2027-03-05 Fri 23 — unknown 19:50–20:35 (good, 0.75 h) 79.1° 15:05 9.47 6% 76.7°
2027-03-06 Sat 21 — unknown 19:50–20:30 (good, 0.67 h) 79.1° 15:00 9.43 2% 65.0°
2027-03-07 Sun 19 — unknown 19:55–20:30 (good, 0.58 h) 79.1° 14:55 9.38 0% 53.1°
2027-03-08 Mon 18 — unknown 19:55–20:25 (good, 0.5 h) 79.1° 14:50 9.33 0% 41.3°
2027-03-09 Tue 16 — unknown 19:55–20:20 (good, 0.42 h) 79.1° 14:50 9.28 3% 29.8°
2027-03-10 Wed 13 — unknown 19:55–20:15 (good, 0.33 h) 79.1° 14:45 9.23 7% 19.5°
2027-03-11 Thu 10 — unknown 20:00–20:05 (good, 0.08 h) 79.1° 14:40 9.19 13% 14.4°
2027-03-12 Fri 8 — unknown 20:00–20:40 (marginal, 0.67 h) 79.1° 14:35 9.14 21% 19.4°
2027-03-13 Sat 6 — unknown 20:00–20:35 (marginal, 0.58 h) 79.1° 14:35 9.09 31% 30.2°
2027-03-14 Sun 4 — unknown 20:00–20:30 (marginal, 0.5 h) 79.1° 14:30 9.04 42% 42.7°
2027-03-15 Mon 3 — unknown 20:00–20:20 (marginal, 0.33 h) 79.1° 14:25 8.99 53% 55.9°
2027-03-16 Tue 2 — unknown 20:05–20:15 (marginal, 0.17 h) 79.1° 14:20 8.94 64% 69.5°
2027-03-17 Wed 2 — unknown 20:05–20:15 (marginal, 0.17 h) 79.1° 14:15 8.89 75% 83.3°
2027-03-18 Thu 2 — unknown 20:05–20:15 (marginal, 0.17 h) 79.1° 14:15 8.84 84% 97.3°
2027-03-19 Fri 2 — unknown 20:05–20:10 (marginal, 0.08 h) 79.1° 14:10 8.79 92% 111.3°
2027-03-20 Sat 1 — unknown — 79.1° 14:05 8.73 97% 125.2°
2027-03-21 Sun 1 — unknown — 79.1° 14:00 8.68 100% 138.6°
2027-03-22 Mon 1 — unknown — 79.1° 13:55 8.63 100% 151.3°
2027-03-23 Tue 1 — unknown — 79.1° 13:55 8.58 97% 161.7°
2027-03-24 Wed 0 — unknown — 79.1° 13:50 8.53 92% 165.4°
2027-03-25 Thu 0 — unknown — 79.1° 13:45 8.47 86% 159.3°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2027-02-24&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.