← 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 North America Nebula: 07-08 (100), 07-09 (100), 07-10 (100), 07-11 (100), 07-12 (100) — by astronomy; check the weather when the night is within four days.
2026-07-08astronomy score per night — click a bar for that night2026-08-06
night ofastronomyweatheroverall best windowhighestdark hMoonMoon sep.
2026-07-08 Wed 100 0 0 — 87.2° 03:15 4.73 38% 66.5°
2026-07-09 Thu 100 91 91 23:05–03:50 (good, 4.75 h) 87.3° 03:10 4.76 27% 73.0°
2026-07-10 Fri 100 97 97 23:05–03:55 (good, 4.83 h) 87.3° 03:05 4.8 17% 80.5°
2026-07-11 Sat 100 100 100 23:05–03:55 (good, 4.83 h) 87.3° 03:00 4.84 9% 88.6°
2026-07-12 Sun 100 89 89 23:05–03:55 (good, 4.83 h) 87.2° 02:55 4.87 3% 96.9°
2026-07-13 Mon 100 89 89 23:00–03:55 (good, 4.92 h) 87.2° 02:55 4.91 0% 104.9°
2026-07-14 Tue 100 98 98 23:00–04:00 (good, 5.0 h) 87.3° 02:50 4.96 0% 112.0°
2026-07-15 Wed 100 57 57 02:00–04:00 (good, 2.0 h) 87.3° 02:45 5.0 3% 117.8°
2026-07-16 Thu 100 22 22 23:00–00:00 (good, 1.0 h) 87.2° 02:40 5.04 9% 121.8°
2026-07-17 Fri 100 98 98 22:55–04:00 (good, 5.08 h) 87.2° 02:40 5.08 16% 123.6°
2026-07-18 Sat 100 94 94 22:55–04:05 (good, 5.17 h) 87.2° 02:35 5.13 25% 123.2°
2026-07-19 Sun 100 98 98 22:55–04:05 (good, 5.17 h) 87.3° 02:30 5.18 35% 120.9°
2026-07-20 Mon 100 54 54 02:00–04:05 (good, 2.08 h) 87.3° 02:25 5.22 45% 117.0°
2026-07-21 Tue 100 73 73 23:00–03:00 (good, 4.0 h) 87.2° 02:20 5.27 55% 112.1°
2026-07-22 Wed 100 96 96 22:50–04:10 (good, 5.33 h) 87.2° 02:20 5.32 64% 106.4°
2026-07-23 Thu 100 61 61 23:00–02:00 (good, 3.0 h) 87.3° 02:15 5.37 73% 100.2°
2026-07-24 Fri 100 0 0 — 87.3° 02:10 5.42 81% 93.7°
2026-07-25 Sat 100 87 87 01:00–04:15 (good, 3.25 h) 87.3° 02:05 5.47 88% 87.2°
2026-07-26 Sun 100 86 86 00:00–04:15 (good, 4.25 h) 87.2° 02:00 5.52 93% 80.7°
2026-07-27 Mon 76 99 75 22:45–04:20 (good, 5.58 h) 87.2° 02:00 5.58 97% 74.5°
2026-07-28 Tue 69 90 62 23:00–01:00 (good, 2.0 h) 87.3° 01:55 5.63 100% 68.7°
2026-07-29 Wed 63 100 63 22:40–00:25 (good, 1.75 h) 87.3° 01:50 5.68 100% 63.6°
2026-07-30 Thu 61 100 61 22:40–23:55 (good, 1.25 h) 87.2° 01:45 5.74 98% 59.6°
2026-07-31 Fri 63 100 63 22:35–00:10 (good, 1.58 h) 87.2° 01:45 5.79 95% 57.1°
2026-08-01 Sat 69 100 69 22:35–00:50 (good, 2.25 h) 87.2° 01:40 5.85 89% 56.3°
2026-08-02 Sun 73 99 72 22:35–02:05 (good, 3.5 h) 87.3° 01:35 5.9 82% 57.4°
2026-08-03 Mon 100 99 99 22:30–04:30 (good, 6.0 h) 87.3° 01:30 5.96 73% 60.3°
2026-08-04 Tue 100 95 95 22:30–04:30 (good, 6.0 h) 87.2° 01:25 6.01 63% 65.0°
2026-08-05 Wed 100 90 90 22:30–04:30 (good, 6.0 h) 87.2° 01:25 6.07 52% 71.0°
2026-08-06 Thu 100 90 90 22:25–04:35 (good, 6.17 h) 87.3° 01:20 6.13 40% 78.1°

Download: CSV · JSON


💡 API
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2026-07-08&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.