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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 Andromeda Galaxy: 05-25 (12), 05-24 (11), 05-23 (10), 05-21 (9), 05-22 (9) — by astronomy; check the weather when the night is within four days.
2034-04-26astronomy score per night — click a bar for that night2034-05-25
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2034-04-26 Wed 1 — unknown — 89.7° 11:45 6.65 65% 113.5°
2034-04-27 Thu 1 — unknown — 89.8° 11:40 6.59 74% 122.9°
2034-04-28 Fri 1 — unknown — 89.7° 11:35 6.53 82% 131.2°
2034-04-29 Sat 1 — unknown — 89.5° 11:30 6.48 89% 138.2°
2034-04-30 Sun 1 — unknown — 89.6° 11:30 6.42 94% 142.9°
2034-05-01 Mon 1 — unknown — 89.7° 11:25 6.36 98% 144.6°
2034-05-02 Tue 1 — unknown — 89.8° 11:20 6.3 100% 142.9°
2034-05-03 Wed 1 — unknown — 89.6° 11:15 6.24 100% 138.3°
2034-05-04 Thu 1 — unknown — 89.5° 11:15 6.19 98% 131.6°
2034-05-05 Fri 1 — unknown — 89.6° 11:10 6.13 95% 123.5°
2034-05-06 Sat 1 — unknown — 89.8° 11:05 6.07 90% 114.5°
2034-05-07 Sun 1 — unknown — 89.7° 11:00 6.02 83% 105.0°
2034-05-08 Mon 1 — unknown — 89.6° 10:55 5.96 75% 95.1°
2034-05-09 Tue 1 — unknown — 89.5° 10:55 5.9 66% 84.8°
2034-05-10 Wed 2 — unknown 04:10–04:15 (marginal, 0.08 h) 89.7° 10:50 5.85 56% 74.5°
2034-05-11 Thu 2 — unknown 04:10–04:15 (marginal, 0.08 h) 89.8° 10:45 5.79 45% 64.2°
2034-05-12 Fri 3 — unknown 04:05–04:10 (marginal, 0.08 h) 89.7° 10:40 5.74 34% 54.2°
2034-05-13 Sat 3 — unknown 04:00–04:10 (marginal, 0.17 h) 89.5° 10:35 5.68 24% 45.2°
2034-05-14 Sun 5 — unknown 03:55–04:10 (marginal, 0.25 h) 89.6° 10:35 5.63 15% 38.3°
2034-05-15 Mon 5 — unknown 04:25–04:50 (marginal, 0.42 h) 89.7° 10:30 5.57 7% 35.5°
2034-05-16 Tue 5 — unknown 04:20–04:50 (marginal, 0.5 h) 89.8° 10:25 5.52 2% 37.9°
2034-05-17 Wed 6 — unknown 04:20–04:50 (marginal, 0.5 h) 89.6° 10:20 5.47 0% 44.9°
2034-05-18 Thu 6 — unknown 04:15–04:50 (marginal, 0.58 h) 89.5° 10:20 5.42 1% 54.7°
2034-05-19 Fri 7 — unknown 04:10–04:45 (marginal, 0.58 h) 89.6° 10:15 5.37 5% 65.7°
2034-05-20 Sat 8 — unknown 04:05–04:45 (marginal, 0.67 h) 89.8° 10:10 5.32 11% 77.3°
2034-05-21 Sun 9 — unknown 03:30–04:45 (marginal, 1.25 h) 89.7° 10:05 5.27 20% 88.7°
2034-05-22 Mon 9 — unknown 04:00–04:45 (marginal, 0.75 h) 89.6° 10:00 5.22 29% 99.9°
2034-05-23 Tue 10 — unknown 03:20–04:45 (marginal, 1.42 h) 89.5° 10:00 5.17 39% 110.4°
2034-05-24 Wed 11 — unknown 03:50–03:55 (good, 0.08 h) 89.7° 09:55 5.13 49% 120.2°
2034-05-25 Thu 12 — unknown 03:45–03:55 (good, 0.17 h) 89.8° 09:50 5.08 59% 129.0°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-04-26&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.