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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: 07-25 (19), 07-27 (19), 07-26 (18), 07-28 (18), 07-24 (17) — by astronomy; check the weather when the night is within four days.
2045-07-03astronomy score per night — click a bar for that night2045-08-01
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2045-07-03 Mon 0 — unknown — 72.6° 10:20 4.59 82% 86.7°
2045-07-04 Tue 0 — unknown — 72.6° 10:15 4.62 74% 74.8°
2045-07-05 Wed 0 — unknown — 72.6° 10:10 4.65 65% 62.8°
2045-07-06 Thu 0 — unknown — 72.6° 10:10 4.68 55% 50.6°
2045-07-07 Fri 0 — unknown — 72.6° 10:05 4.71 45% 38.2°
2045-07-08 Sat 0 — unknown — 72.6° 10:00 4.74 35% 25.4°
2045-07-09 Sun 1 — unknown — 72.6° 09:55 4.78 26% 12.2°
2045-07-10 Mon 1 — unknown — 72.6° 09:50 4.81 17% 1.8°
2045-07-11 Tue 1 — unknown — 72.6° 09:50 4.85 9% 15.6°
2045-07-12 Wed 2 — unknown 04:40–04:45 (marginal, 0.08 h) 72.6° 09:45 4.89 3% 30.1°
2045-07-13 Thu 2 — unknown 04:35–04:45 (marginal, 0.17 h) 72.6° 09:40 4.93 0% 45.0°
2045-07-14 Fri 3 — unknown 04:30–04:50 (marginal, 0.33 h) 72.6° 09:35 4.97 0% 60.1°
2045-07-15 Sat 3 — unknown 04:25–04:50 (marginal, 0.42 h) 72.6° 09:30 5.02 3% 75.2°
2045-07-16 Sun 4 — unknown 04:20–04:50 (marginal, 0.5 h) 72.6° 09:30 5.06 9% 90.3°
2045-07-17 Mon 5 — unknown 04:20–04:50 (marginal, 0.5 h) 72.6° 09:25 5.1 17% 105.1°
2045-07-18 Tue 6 — unknown 04:15–04:50 (marginal, 0.58 h) 72.6° 09:20 5.15 27% 119.5°
2045-07-19 Wed 7 — unknown 04:10–04:55 (marginal, 0.75 h) 72.6° 09:15 5.2 38% 133.5°
2045-07-20 Thu 10 — unknown 04:05–04:10 (good, 0.08 h) 72.6° 09:10 5.24 48% 147.2°
2045-07-21 Fri 11 — unknown 04:05–04:10 (good, 0.08 h) 72.6° 09:10 5.29 59% 160.4°
2045-07-22 Sat 12 — unknown 04:00–04:10 (good, 0.17 h) 72.6° 09:05 5.34 69% 173.3°
2045-07-23 Sun 14 — unknown 03:55–04:10 (good, 0.25 h) 72.6° 09:00 5.39 78% 173.9°
2045-07-24 Mon 17 — unknown 03:50–04:15 (good, 0.42 h) 72.6° 08:55 5.44 86% 161.6°
2045-07-25 Tue 19 — unknown 03:45–04:15 (good, 0.5 h) 72.6° 08:55 5.49 92% 149.4°
2045-07-26 Wed 18 — unknown 03:50–04:15 (good, 0.42 h) 72.6° 08:50 5.55 96% 137.3°
2045-07-27 Thu 19 — unknown 03:50–04:20 (good, 0.5 h) 72.6° 08:45 5.6 99% 125.3°
2045-07-28 Fri 18 — unknown 03:50–04:20 (good, 0.5 h) 72.6° 08:40 5.65 100% 113.4°
2045-07-29 Sat 16 — unknown 03:55–04:20 (good, 0.42 h) 72.6° 08:35 5.71 99% 101.6°
2045-07-30 Sun 14 — unknown 04:20–04:25 (good, 0.08 h) 72.6° 08:35 5.76 96% 89.8°
2045-07-31 Mon 13 — unknown 03:05–04:25 (marginal, 1.33 h) 72.6° 08:30 5.81 92% 77.9°
2045-08-01 Tue 11 — unknown 03:05–04:25 (marginal, 1.33 h) 72.6° 08:25 5.87 86% 66.0°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-07-03&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.