← 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 3C 273: 07-07 (3), 07-08 (3), 07-09 (2), 07-10 (2), 07-11 (2) — by astronomy; check the weather when the night is within four days.
2043-07-07astronomy score per night — click a bar for that night2043-08-05
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2043-07-07 Tue 3 — unknown 22:15–22:40 (marginal, 0.42 h) 50.1° 18:50 4.69 2% 63.9°
2043-07-08 Wed 3 — unknown 22:15–22:35 (marginal, 0.33 h) 50.1° 18:45 4.73 6% 49.9°
2043-07-09 Thu 2 — unknown 22:15–22:30 (marginal, 0.25 h) 50.1° 18:40 4.76 13% 36.4°
2043-07-10 Fri 2 — unknown 22:15–22:20 (marginal, 0.08 h) 50.1° 18:40 4.8 21% 23.4°
2043-07-11 Sat 2 — unknown — 50.1° 18:35 4.83 30% 11.3°
2043-07-12 Sun 1 — unknown — 50.1° 18:30 4.87 39% 5.6°
2043-07-13 Mon 1 — unknown — 50.1° 18:25 4.91 49% 15.3°
2043-07-14 Tue 1 — unknown — 50.1° 18:25 4.95 58% 26.9°
2043-07-15 Wed 1 — unknown — 50.1° 18:20 4.99 67% 38.6°
2043-07-16 Thu 1 — unknown — 50.1° 18:15 5.04 76% 50.4°
2043-07-17 Fri 0 — unknown — 50.1° 18:10 5.08 84% 62.2°
2043-07-18 Sat 0 — unknown — 50.1° 18:05 5.13 90% 74.1°
2043-07-19 Sun 0 — unknown — 50.1° 18:05 5.17 95% 86.2°
2043-07-20 Mon 0 — unknown — 50.1° 18:00 5.22 98% 98.5°
2043-07-21 Tue 0 — unknown — 50.1° 17:55 5.27 100% 111.0°
2043-07-22 Wed 0 — unknown — 50.1° 17:50 5.32 99% 123.7°
2043-07-23 Thu 0 — unknown — 50.1° 17:45 5.37 96% 136.7°
2043-07-24 Fri 0 — unknown — 50.1° 17:45 5.42 92% 149.7°
2043-07-25 Sat 0 — unknown — 50.1° 17:40 5.47 85% 162.8°
2043-07-26 Sun 0 — unknown — 50.1° 17:35 5.52 76% 174.1°
2043-07-27 Mon 0 — unknown — 50.1° 17:30 5.57 66% 167.8°
2043-07-28 Tue 0 — unknown — 50.1° 17:30 5.62 55% 154.5°
2043-07-29 Wed 0 — unknown — 50.1° 17:25 5.68 43% 140.6°
2043-07-30 Thu 0 — unknown — 50.1° 17:20 5.73 32% 126.4°
2043-07-31 Fri 0 — unknown — 50.1° 17:15 5.79 22% 112.2°
2043-08-01 Sat 0 — unknown — 50.1° 17:10 5.84 13% 97.8°
2043-08-02 Sun 0 — unknown — 50.1° 17:10 5.9 6% 83.5°
2043-08-03 Mon 0 — unknown — 50.1° 17:05 5.95 2% 69.4°
2043-08-04 Tue 0 — unknown — 50.1° 17:00 6.01 0% 55.4°
2043-08-05 Wed 0 — unknown — 50.1° 16:55 6.06 1% 41.7°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-07-07&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.