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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: 03-18 (36), 03-19 (36), 03-16 (34), 03-20 (34), 03-17 (33) — by astronomy; check the weather when the night is within four days.
2033-03-15astronomy score per night — click a bar for that night2033-04-13
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2033-03-15 Tue 32 — unknown 20:05–21:30 (good, 1.42 h) 72.6° 16:35 8.96 100% 114.5°
2033-03-16 Wed 34 — unknown 20:05–21:30 (good, 1.42 h) 72.6° 16:30 8.91 99% 126.2°
2033-03-17 Thu 33 — unknown 20:05–21:30 (good, 1.42 h) 72.6° 16:30 8.86 97% 137.9°
2033-03-18 Fri 36 — unknown 20:05–21:30 (good, 1.42 h) 72.6° 16:25 8.81 93% 149.6°
2033-03-19 Sat 36 — unknown 20:10–21:30 (good, 1.33 h) 72.6° 16:20 8.76 87% 161.0°
2033-03-20 Sun 34 — unknown 20:10–21:25 (good, 1.25 h) 72.6° 16:15 8.71 80% 170.8°
2033-03-21 Mon 32 — unknown 20:10–21:25 (good, 1.25 h) 72.6° 16:10 8.65 71% 169.8°
2033-03-22 Tue 30 — unknown 20:10–21:20 (good, 1.17 h) 72.6° 16:10 8.6 62% 159.1°
2033-03-23 Wed 28 — unknown 20:15–21:15 (good, 1.0 h) 72.6° 16:05 8.55 52% 146.7°
2033-03-24 Thu 26 — unknown 20:15–21:10 (good, 0.92 h) 72.6° 16:00 8.5 41% 133.7°
2033-03-25 Fri 25 — unknown 20:15–21:05 (good, 0.83 h) 72.6° 15:55 8.44 30% 120.1°
2033-03-26 Sat 23 — unknown 20:15–21:05 (good, 0.83 h) 72.6° 15:50 8.39 20% 106.1°
2033-03-27 Sun 21 — unknown 21:20–22:00 (good, 0.67 h) 72.6° 16:50 8.34 12% 91.6°
2033-03-28 Mon 20 — unknown 21:20–21:55 (good, 0.58 h) 72.6° 16:45 8.28 5% 76.7°
2033-03-29 Tue 18 — unknown 21:20–21:50 (good, 0.5 h) 72.6° 16:40 8.23 1% 61.7°
2033-03-30 Wed 16 — unknown 21:20–21:50 (good, 0.5 h) 72.6° 16:35 8.18 0% 46.7°
2033-03-31 Thu 13 — unknown 21:25–21:45 (good, 0.33 h) 72.6° 16:35 8.12 2% 31.9°
2033-04-01 Fri 11 — unknown 21:25–21:35 (good, 0.17 h) 72.6° 16:30 8.07 7% 17.8°
2033-04-02 Sat 9 — unknown 21:25–21:30 (good, 0.08 h) 72.6° 16:25 8.01 14% 7.7°
2033-04-03 Sun 6 — unknown 21:30–22:00 (marginal, 0.5 h) 72.6° 16:20 7.96 23% 14.3°
2033-04-04 Mon 4 — unknown 21:30–21:55 (marginal, 0.42 h) 72.6° 16:15 7.9 33% 26.7°
2033-04-05 Tue 3 — unknown 21:30–21:50 (marginal, 0.33 h) 72.6° 16:15 7.84 43% 39.4°
2033-04-06 Wed 2 — unknown 21:30–21:45 (marginal, 0.25 h) 72.6° 16:10 7.79 53% 51.9°
2033-04-07 Thu 2 — unknown 21:35–21:40 (marginal, 0.08 h) 72.6° 16:05 7.73 63% 64.1°
2033-04-08 Fri 1 — unknown — 72.6° 16:00 7.68 72% 76.1°
2033-04-09 Sat 1 — unknown — 72.6° 15:55 7.62 80% 87.9°
2033-04-10 Sun 1 — unknown — 72.6° 15:55 7.56 87% 99.7°
2033-04-11 Mon 1 — unknown — 72.6° 15:50 7.51 93% 111.4°
2033-04-12 Tue 1 — unknown — 72.6° 15:45 7.45 97% 123.1°
2033-04-13 Wed 1 — unknown — 72.6° 15:40 7.39 99% 134.8°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-03-15&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.