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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: 07-22 (13), 07-21 (11), 07-20 (9), 07-19 (7), 07-18 (5) — by astronomy; check the weather when the night is within four days.
2036-06-23astronomy score per night — click a bar for that night2036-07-22
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2036-06-23 Mon 0 — unknown — 72.5° 10:55 4.43 0% 31.5°
2036-06-24 Tue 0 — unknown — 72.5° 10:55 4.44 1% 45.9°
2036-06-25 Wed 0 — unknown — 72.5° 10:50 4.45 5% 60.7°
2036-06-26 Thu 0 — unknown — 72.5° 10:45 4.46 11% 75.4°
2036-06-27 Fri 0 — unknown — 72.5° 10:40 4.48 20% 89.9°
2036-06-28 Sat 0 — unknown — 72.5° 10:40 4.49 30% 104.2°
2036-06-29 Sun 0 — unknown — 72.5° 10:35 4.51 41% 118.0°
2036-06-30 Mon 0 — unknown — 72.5° 10:30 4.53 52% 131.5°
2036-07-01 Tue 0 — unknown — 72.5° 10:25 4.55 63% 144.4°
2036-07-02 Wed 0 — unknown — 72.5° 10:20 4.57 72% 156.7°
2036-07-03 Thu 0 — unknown — 72.5° 10:20 4.6 81% 167.4°
2036-07-04 Fri 0 — unknown — 72.5° 10:15 4.63 88% 170.0°
2036-07-05 Sat 0 — unknown — 72.5° 10:10 4.65 94% 161.4°
2036-07-06 Sun 0 — unknown — 72.5° 10:05 4.69 98% 150.3°
2036-07-07 Mon 1 — unknown — 72.5° 10:00 4.72 100% 138.7°
2036-07-08 Tue 1 — unknown — 72.5° 10:00 4.75 100% 127.0°
2036-07-09 Wed 1 — unknown — 72.5° 09:55 4.79 98% 115.3°
2036-07-10 Thu 1 — unknown — 72.5° 09:50 4.82 95% 103.7°
2036-07-11 Fri 1 — unknown — 72.5° 09:45 4.86 90% 92.0°
2036-07-12 Sat 1 — unknown — 72.5° 09:45 4.9 83% 80.3°
2036-07-13 Sun 1 — unknown — 72.5° 09:40 4.94 75% 68.5°
2036-07-14 Mon 1 — unknown — 72.5° 09:35 4.98 66% 56.5°
2036-07-15 Tue 1 — unknown — 72.5° 09:30 5.02 57% 44.4°
2036-07-16 Wed 2 — unknown 03:55–04:00 (marginal, 0.08 h) 72.5° 09:25 5.07 47% 32.2°
2036-07-17 Thu 3 — unknown 03:50–04:05 (marginal, 0.25 h) 72.5° 09:25 5.11 36% 20.1°
2036-07-18 Fri 5 — unknown 04:25–04:50 (marginal, 0.42 h) 72.5° 09:20 5.16 26% 10.3°
2036-07-19 Sat 7 — unknown 04:15–04:55 (marginal, 0.67 h) 72.5° 09:15 5.2 17% 13.2°
2036-07-20 Sun 9 — unknown 03:40–04:55 (marginal, 1.25 h) 72.5° 09:10 5.25 9% 25.5°
2036-07-21 Mon 11 — unknown 04:00–04:10 (good, 0.17 h) 72.5° 09:05 5.3 3% 39.5°
2036-07-22 Tue 13 — unknown 04:00–04:10 (good, 0.17 h) 72.5° 09:05 5.35 0% 54.2°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-06-23&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.