← single night · whole-night plan

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: 03-29 (18), 03-30 (16), 03-31 (13), 04-01 (12), 04-02 (11) — by astronomy; check the weather when the night is within four days.
2030-03-29astronomy score per night — click a bar for that night2030-04-27
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2030-03-29 Fri 18 — unknown 20:20–20:50 (good, 0.5 h) 72.5° 15:40 8.24 16% 96.5°
2030-03-30 Sat 16 — unknown 20:20–20:50 (good, 0.5 h) 72.5° 15:35 8.19 9% 83.6°
2030-03-31 Sun 13 — unknown 21:25–21:45 (good, 0.33 h) 72.5° 16:35 8.14 4% 71.0°
2030-04-01 Mon 12 — unknown 21:25–21:40 (good, 0.25 h) 72.5° 16:30 8.08 1% 58.5°
2030-04-02 Tue 11 — unknown 21:25–21:35 (good, 0.17 h) 72.5° 16:25 8.03 0% 46.2°
2030-04-03 Wed 9 — unknown 21:25–21:30 (good, 0.08 h) 72.5° 16:20 7.97 1% 34.1°
2030-04-04 Thu 7 — unknown 21:30–21:55 (marginal, 0.42 h) 72.5° 16:20 7.91 4% 22.2°
2030-04-05 Fri 5 — unknown 21:30–21:50 (marginal, 0.33 h) 72.5° 16:15 7.86 8% 10.4°
2030-04-06 Sat 4 — unknown 21:30–21:50 (marginal, 0.33 h) 72.5° 16:10 7.8 14% 3.0°
2030-04-07 Sun 3 — unknown 21:35–21:45 (marginal, 0.17 h) 72.5° 16:05 7.75 21% 13.7°
2030-04-08 Mon 2 — unknown 21:35–21:40 (marginal, 0.08 h) 72.5° 16:00 7.69 29% 25.5°
2030-04-09 Tue 1 — unknown — 72.5° 16:00 7.63 38% 37.4°
2030-04-10 Wed 1 — unknown — 72.5° 15:55 7.58 48% 49.6°
2030-04-11 Thu 1 — unknown — 72.5° 15:50 7.52 58% 62.0°
2030-04-12 Fri 0 — unknown — 72.5° 15:45 7.46 68% 74.8°
2030-04-13 Sat 0 — unknown — 72.5° 15:40 7.41 77% 88.1°
2030-04-14 Sun 0 — unknown — 72.5° 15:40 7.35 86% 101.8°
2030-04-15 Mon 0 — unknown — 72.5° 15:35 7.29 93% 115.9°
2030-04-16 Tue 0 — unknown — 72.5° 15:30 7.23 98% 130.5°
2030-04-17 Wed 0 — unknown — 72.5° 15:25 7.18 100% 145.4°
2030-04-18 Thu 0 — unknown — 72.5° 15:25 7.12 99% 160.4°
2030-04-19 Fri 0 — unknown — 72.5° 15:20 7.06 95% 175.0°
2030-04-20 Sat 0 — unknown — 72.5° 15:15 7.0 89% 169.1°
2030-04-21 Sun 0 — unknown — 72.5° 15:10 6.94 80% 154.5°
2030-04-22 Mon 0 — unknown — 72.5° 15:05 6.89 70% 140.2°
2030-04-23 Tue 0 — unknown — 72.5° 15:05 6.83 59% 126.2°
2030-04-24 Wed 0 — unknown — 72.5° 15:00 6.77 48% 112.7°
2030-04-25 Thu 0 — unknown — 72.5° 14:55 6.71 38% 99.5°
2030-04-26 Fri 0 — unknown — 72.5° 14:50 6.65 28% 86.6°
2030-04-27 Sat 0 — unknown — 72.5° 14:45 6.59 20% 74.0°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-03-29&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.