{"assessment":{"best_window":{"end":"2025-10-01T02:50Z","end_local":"05:50","hours":5.83,"label":"good","mean_quality":0.91,"start":"2025-09-30T21:00Z","start_local":"00:00"},"cost":{"altitude":0.0,"clouds":3.14,"darkness":2.46,"moon":1.11},"formula":"astronomy = 100 * min(1, sky_hours / reference_hours) * peak_sky; overall = astronomy * score_weather / 100 (null when the weather is unknown)","hard_limit":null,"headline":"Possible, with compromises","hourly":[{"alt":null,"cloud":100,"high":0,"iso":"2025-09-30T16:00Z","label":"unusable","low":100,"mid":3,"moon_alt":19,"precip":0.0,"q":0.0,"rh":86,"sky":"civil twilight","temp":5.1,"time":"19:00","wind":2.3},{"alt":null,"cloud":99,"high":0,"iso":"2025-09-30T17:00Z","label":"unusable","low":99,"mid":36,"moon_alt":20,"precip":0.0,"q":0.0,"rh":92,"sky":"nautical twilight","temp":4.8,"time":"20:00","wind":1.5},{"alt":null,"cloud":94,"high":0,"iso":"2025-09-30T18:00Z","label":"unusable","low":94,"mid":13,"moon_alt":19,"precip":0.0,"q":0.0,"rh":92,"sky":"night","temp":4.7,"time":"21:00","wind":1.3},{"alt":null,"cloud":86,"high":0,"iso":"2025-09-30T19:00Z","label":"unusable","low":86,"mid":0,"moon_alt":15,"precip":0.0,"q":0.0,"rh":89,"sky":"night","temp":4.4,"time":"22:00","wind":0.2},{"alt":null,"cloud":82,"high":0,"iso":"2025-09-30T20:00Z","label":"unusable","low":82,"mid":0,"moon_alt":9,"precip":0.0,"q":0.0,"rh":88,"sky":"night","temp":3.4,"time":"23:00","wind":0.9},{"alt":null,"cloud":9,"high":0,"iso":"2025-09-30T21:00Z","label":"good","low":9,"mid":0,"moon_alt":1,"precip":0.0,"q":0.68,"rh":90,"sky":"night","temp":3.0,"time":"00:00","wind":0.8},{"alt":null,"cloud":18,"high":0,"iso":"2025-09-30T22:00Z","label":"good","low":18,"mid":0,"moon_alt":-7,"precip":0.0,"q":0.8,"rh":89,"sky":"night","temp":2.1,"time":"01:00","wind":1.5},{"alt":null,"cloud":11,"high":0,"iso":"2025-09-30T23:00Z","label":"good","low":11,"mid":0,"moon_alt":-17,"precip":0.0,"q":0.88,"rh":88,"sky":"night","temp":1.6,"time":"02:00","wind":1.8},{"alt":null,"cloud":2,"high":0,"iso":"2025-10-01T00:00Z","label":"good","low":2,"mid":1,"moon_alt":-27,"precip":0.0,"q":0.98,"rh":85,"sky":"night","temp":2.0,"time":"03:00","wind":1.5},{"alt":null,"cloud":0,"high":0,"iso":"2025-10-01T01:00Z","label":"good","low":0,"mid":0,"moon_alt":-38,"precip":0.0,"q":1.0,"rh":84,"sky":"night","temp":1.2,"time":"04:00","wind":0.4},{"alt":null,"cloud":7,"high":0,"iso":"2025-10-01T02:00Z","label":"good","low":7,"mid":0,"moon_alt":-48,"precip":0.0,"q":0.92,"rh":82,"sky":"night","temp":0.9,"time":"05:00","wind":0.3},{"alt":null,"cloud":1,"high":0,"iso":"2025-10-01T03:00Z","label":"marginal","low":1,"mid":0,"moon_alt":-59,"precip":0.0,"q":0.49,"rh":81,"sky":"astronomical twilight","temp":0.6,"time":"06:00","wind":0.4},{"alt":null,"cloud":1,"high":0,"iso":"2025-10-01T04:00Z","label":"unusable","low":1,"mid":0,"moon_alt":-68,"precip":0.0,"q":0.0,"rh":81,"sky":"civil twilight","temp":0.1,"time":"07:00","wind":1.3}],"peak_quality":1.0,"peak_sky":1.0,"quality_hours":5.62,"reasons":["cloud cover cost 3.1 quality-hours","daylight and twilight cost 2.5 quality-hours","moonlight cost 1.1 quality-hours"],"reference_hours":4.0,"score":64,"score_astronomy":100,"score_weather":64,"sky_hours":8.76,"verdict":"marginal","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2025-09-30T21:00Z","end_local":"00:00","hours":5.0,"label":"unusable","mean_quality":0.0,"start":"2025-09-30T16:00Z","start_local":"19:00"},{"end":"2025-10-01T02:50Z","end_local":"05:50","hours":5.83,"label":"good","mean_quality":0.91,"start":"2025-09-30T21:00Z","start_local":"00:00"},{"end":"2025-10-01T03:20Z","end_local":"06:20","hours":0.5,"label":"marginal","mean_quality":0.48,"start":"2025-10-01T02:50Z","start_local":"05:50"},{"end":"2025-10-01T03:55Z","end_local":"06:55","hours":0.58,"label":"poor","mean_quality":0.15,"start":"2025-10-01T03:20Z","start_local":"06:20"},{"end":"2025-10-01T04:20Z","end_local":"07:20","hours":0.42,"label":"unusable","mean_quality":0.0,"start":"2025-10-01T03:55Z","start_local":"06:55"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":100,"dark":false,"high":0,"local":"19:00","low":100,"mid":3,"precip":0.0,"rh":86,"temp":5.1,"time":"2025-09-30T16:00Z","wind":2.3},{"cloud":99,"dark":false,"high":0,"local":"20:00","low":99,"mid":36,"precip":0.0,"rh":92,"temp":4.8,"time":"2025-09-30T17:00Z","wind":1.5},{"cloud":94,"dark":true,"high":0,"local":"21:00","low":94,"mid":13,"precip":0.0,"rh":92,"temp":4.7,"time":"2025-09-30T18:00Z","wind":1.3},{"cloud":86,"dark":true,"high":0,"local":"22:00","low":86,"mid":0,"precip":0.0,"rh":89,"temp":4.4,"time":"2025-09-30T19:00Z","wind":0.2},{"cloud":82,"dark":true,"high":0,"local":"23:00","low":82,"mid":0,"precip":0.0,"rh":88,"temp":3.4,"time":"2025-09-30T20:00Z","wind":0.9},{"cloud":9,"dark":true,"high":0,"local":"00:00","low":9,"mid":0,"precip":0.0,"rh":90,"temp":3.0,"time":"2025-09-30T21:00Z","wind":0.8},{"cloud":18,"dark":true,"high":0,"local":"01:00","low":18,"mid":0,"precip":0.0,"rh":89,"temp":2.1,"time":"2025-09-30T22:00Z","wind":1.5},{"cloud":11,"dark":true,"high":0,"local":"02:00","low":11,"mid":0,"precip":0.0,"rh":88,"temp":1.6,"time":"2025-09-30T23:00Z","wind":1.8},{"cloud":2,"dark":true,"high":0,"local":"03:00","low":2,"mid":1,"precip":0.0,"rh":85,"temp":2.0,"time":"2025-10-01T00:00Z","wind":1.5},{"cloud":0,"dark":true,"high":0,"local":"04:00","low":0,"mid":0,"precip":0.0,"rh":84,"temp":1.2,"time":"2025-10-01T01:00Z","wind":0.4},{"cloud":7,"dark":true,"high":0,"local":"05:00","low":7,"mid":0,"precip":0.0,"rh":82,"temp":0.9,"time":"2025-10-01T02:00Z","wind":0.3},{"cloud":1,"dark":false,"high":0,"local":"06:00","low":1,"mid":0,"precip":0.0,"rh":81,"temp":0.6,"time":"2025-10-01T03:00Z","wind":0.4},{"cloud":1,"dark":false,"high":0,"local":"07:00","low":1,"mid":0,"precip":0.0,"rh":81,"temp":0.1,"time":"2025-10-01T04:00Z","wind":1.3},{"cloud":3,"dark":false,"high":2,"local":"08:00","low":0,"mid":0,"precip":0.0,"rh":80,"temp":1.2,"time":"2025-10-01T05:00Z","wind":1.9}],"forecast_source":"history","forecast_updated_at":"2026-10-22T07:46:31Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-09-30T17:36:47Z","dark_hours":9.14,"dark_to":"2025-10-01T02:45:22Z","moon":{"illumination":0.591,"phase":"waxing gibbous","waxing":true},"moon_free_dark_hours":5.6,"moonrise":"2025-09-30T12:42:06Z","moonset":"2025-09-30T21:08:24Z","sunrise":"2025-10-01T04:17:55Z","sunset":"2025-09-30T16:04:23Z","twilight":{"astronomical":{"end":"2025-09-30T17:36:47Z","start":"2025-10-01T02:45:22Z"},"civil":{"end":"2025-09-30T16:32:03Z","start":"2025-10-01T03:50:13Z"},"nautical":{"end":"2025-09-30T17:04:14Z","start":"2025-10-01T03:17:58Z"}},"window_end":"2025-10-01T09:00:00Z","window_start":"2025-09-30T09:00:00Z"},"night_date":"2025-09-30","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}