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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 Seven Sisters: 02-14 (100), 02-15 (100), 02-16 (100), 02-17 (100), 02-18 (100) — by astronomy; check the weather when the night is within four days.
2028-02-14astronomy score per night — click a bar for that night2028-03-14
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2028-02-14 Mon 100 — unknown 19:30–23:35 (good, 4.08 h) 72.5° 18:30 10.3 75% 146.0°
2028-02-15 Tue 100 — unknown 19:30–23:40 (good, 4.17 h) 72.5° 18:30 10.27 65% 159.8°
2028-02-16 Wed 100 — unknown 19:30–23:35 (good, 4.08 h) 72.5° 18:25 10.23 54% 173.2°
2028-02-17 Thu 100 — unknown 19:30–23:30 (good, 4.0 h) 72.5° 18:20 10.18 44% 173.8°
2028-02-18 Fri 100 — unknown 19:35–23:25 (good, 3.83 h) 72.5° 18:15 10.14 34% 161.2°
2028-02-19 Sat 100 — unknown 19:35–23:25 (good, 3.83 h) 72.5° 18:15 10.1 25% 148.9°
2028-02-20 Sun 97 — unknown 19:35–23:20 (good, 3.75 h) 72.5° 18:10 10.06 17% 136.7°
2028-02-21 Mon 96 — unknown 19:35–23:15 (good, 3.67 h) 72.5° 18:05 10.02 10% 124.7°
2028-02-22 Tue 94 — unknown 19:35–23:10 (good, 3.58 h) 72.5° 18:00 9.98 6% 112.8°
2028-02-23 Wed 91 — unknown 19:40–23:10 (good, 3.5 h) 72.5° 17:55 9.93 2% 101.0°
2028-02-24 Thu 89 — unknown 19:40–23:05 (good, 3.42 h) 72.5° 17:55 9.89 0% 89.2°
2028-02-25 Fri 87 — unknown 19:40–23:00 (good, 3.33 h) 72.5° 17:50 9.85 0% 77.3°
2028-02-26 Sat 86 — unknown 19:40–22:55 (good, 3.25 h) 72.5° 17:45 9.8 2% 65.5°
2028-02-27 Sun 80 — unknown 19:45–22:50 (good, 3.08 h) 72.5° 17:40 9.76 6% 53.5°
2028-02-28 Mon 74 — unknown 19:45–22:50 (good, 3.08 h) 72.5° 17:35 9.71 11% 41.5°
2028-02-29 Tue 64 — unknown 19:45–22:45 (good, 3.0 h) 72.5° 17:35 9.67 18% 29.3°
2028-03-01 Wed 53 — unknown 19:45–22:30 (good, 2.75 h) 72.5° 17:30 9.62 26% 16.9°
2028-03-02 Thu 42 — unknown 19:50–22:15 (good, 2.42 h) 72.5° 17:25 9.58 35% 4.2°
2028-03-03 Fri 32 — unknown 19:50–21:10 (good, 1.33 h) 72.5° 17:20 9.53 45% 8.7°
2028-03-04 Sat 22 — unknown 19:50–22:45 (marginal, 2.92 h) 72.5° 17:15 9.48 56% 22.0°
2028-03-05 Sun 17 — unknown 19:50–22:30 (marginal, 2.67 h) 72.5° 17:15 9.44 67% 35.7°
2028-03-06 Mon 16 — unknown 19:55–22:25 (marginal, 2.5 h) 72.5° 17:10 9.39 77% 49.9°
2028-03-07 Tue 18 — unknown 19:55–22:25 (marginal, 2.5 h) 72.5° 17:05 9.34 86% 64.5°
2028-03-08 Wed 23 — unknown 19:20–22:25 (marginal, 3.08 h) 72.5° 17:00 9.29 93% 79.4°
2028-03-09 Thu 30 — unknown 19:55–21:10 (good, 1.25 h) 72.5° 17:00 9.25 98% 94.6°
2028-03-10 Fri 37 — unknown 19:55–21:45 (good, 1.83 h) 72.5° 16:55 9.2 100% 109.8°
2028-03-11 Sat 42 — unknown 20:00–21:50 (good, 1.83 h) 72.5° 16:50 9.15 99% 124.9°
2028-03-12 Sun 47 — unknown 20:00–21:50 (good, 1.83 h) 72.5° 16:45 9.1 95% 139.8°
2028-03-13 Mon 47 — unknown 20:00–21:55 (good, 1.92 h) 72.5° 16:40 9.05 88% 154.3°
2028-03-14 Tue 45 — unknown 20:00–21:50 (good, 1.83 h) 72.5° 16:40 9.0 80% 168.3°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-02-14&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.