{"assessment":{"best_window":{"end":"2025-09-19T02:35Z","end_local":"05:35","hours":8.58,"label":"good","mean_quality":0.99,"start":"2025-09-18T18:00Z","start_local":"21:00"},"cost":{"altitude":0.0,"clouds":0.0,"darkness":2.49,"moon":0.06},"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":"Worth it","hourly":[{"alt":null,"cloud":0,"high":0,"iso":"2025-09-18T17:00Z","label":"poor","low":0,"mid":0,"moon_alt":-19,"precip":0.0,"q":0.15,"rh":60,"sky":"nautical twilight","temp":6.4,"time":"20:00","wind":5.1},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-18T18:00Z","label":"good","low":0,"mid":0,"moon_alt":-26,"precip":0.0,"q":1.0,"rh":66,"sky":"night","temp":5.2,"time":"21:00","wind":4.4},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-18T19:00Z","label":"good","low":0,"mid":0,"moon_alt":-30,"precip":0.0,"q":1.0,"rh":70,"sky":"night","temp":4.3,"time":"22:00","wind":4.3},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-18T20:00Z","label":"good","low":0,"mid":0,"moon_alt":-32,"precip":0.0,"q":1.0,"rh":71,"sky":"night","temp":3.9,"time":"23:00","wind":4.5},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-18T21:00Z","label":"good","low":0,"mid":0,"moon_alt":-31,"precip":0.0,"q":1.0,"rh":72,"sky":"night","temp":3.4,"time":"00:00","wind":4.7},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-18T22:00Z","label":"good","low":0,"mid":0,"moon_alt":-28,"precip":0.0,"q":1.0,"rh":73,"sky":"night","temp":3.3,"time":"01:00","wind":5.2},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-18T23:00Z","label":"good","low":0,"mid":0,"moon_alt":-21,"precip":0.0,"q":1.0,"rh":74,"sky":"night","temp":3.1,"time":"02:00","wind":5.5},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-19T00:00Z","label":"good","low":0,"mid":0,"moon_alt":-13,"precip":0.0,"q":1.0,"rh":75,"sky":"night","temp":3.1,"time":"03:00","wind":6.2},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-19T01:00Z","label":"good","low":0,"mid":0,"moon_alt":-4,"precip":0.0,"q":1.0,"rh":71,"sky":"night","temp":3.2,"time":"04:00","wind":7.3},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-19T02:00Z","label":"good","low":0,"mid":0,"moon_alt":6,"precip":0.0,"q":0.96,"rh":73,"sky":"night","temp":2.9,"time":"05:00","wind":5.9},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-19T03:00Z","label":"marginal","low":0,"mid":0,"moon_alt":17,"precip":0.0,"q":0.48,"rh":77,"sky":"astronomical twilight","temp":2.3,"time":"06:00","wind":5.4},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-19T04:00Z","label":"unusable","low":0,"mid":0,"moon_alt":27,"precip":0.0,"q":0.0,"rh":78,"sky":"civil twilight","temp":2.0,"time":"07:00","wind":5.4}],"peak_quality":1.0,"peak_sky":1.0,"quality_hours":9.2,"reasons":["daylight and twilight cost 2.5 quality-hours"],"reference_hours":4.0,"score":100,"score_astronomy":100,"score_weather":100,"sky_hours":9.2,"verdict":"good","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2025-09-18T16:55Z","end_local":"19:55","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2025-09-18T16:25Z","start_local":"19:25"},{"end":"2025-09-18T17:30Z","end_local":"20:30","hours":0.58,"label":"poor","mean_quality":0.15,"start":"2025-09-18T16:55Z","start_local":"19:55"},{"end":"2025-09-18T18:00Z","end_local":"21:00","hours":0.5,"label":"marginal","mean_quality":0.5,"start":"2025-09-18T17:30Z","start_local":"20:30"},{"end":"2025-09-19T02:35Z","end_local":"05:35","hours":8.58,"label":"good","mean_quality":0.99,"start":"2025-09-18T18:00Z","start_local":"21:00"},{"end":"2025-09-19T03:05Z","end_local":"06:05","hours":0.5,"label":"marginal","mean_quality":0.48,"start":"2025-09-19T02:35Z","start_local":"05:35"},{"end":"2025-09-19T03:40Z","end_local":"06:40","hours":0.58,"label":"poor","mean_quality":0.14,"start":"2025-09-19T03:05Z","start_local":"06:05"},{"end":"2025-09-19T04:10Z","end_local":"07:10","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2025-09-19T03:40Z","start_local":"06:40"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":1,"dark":false,"high":0,"local":"19:00","low":1,"mid":0,"precip":0.0,"rh":49,"temp":8.9,"time":"2025-09-18T16:00Z","wind":8.9},{"cloud":0,"dark":false,"high":0,"local":"20:00","low":0,"mid":0,"precip":0.0,"rh":60,"temp":6.4,"time":"2025-09-18T17:00Z","wind":5.1},{"cloud":0,"dark":true,"high":0,"local":"21:00","low":0,"mid":0,"precip":0.0,"rh":66,"temp":5.2,"time":"2025-09-18T18:00Z","wind":4.4},{"cloud":0,"dark":true,"high":0,"local":"22:00","low":0,"mid":0,"precip":0.0,"rh":70,"temp":4.3,"time":"2025-09-18T19:00Z","wind":4.3},{"cloud":0,"dark":true,"high":0,"local":"23:00","low":0,"mid":0,"precip":0.0,"rh":71,"temp":3.9,"time":"2025-09-18T20:00Z","wind":4.5},{"cloud":0,"dark":true,"high":0,"local":"00:00","low":0,"mid":0,"precip":0.0,"rh":72,"temp":3.4,"time":"2025-09-18T21:00Z","wind":4.7},{"cloud":0,"dark":true,"high":0,"local":"01:00","low":0,"mid":0,"precip":0.0,"rh":73,"temp":3.3,"time":"2025-09-18T22:00Z","wind":5.2},{"cloud":0,"dark":true,"high":0,"local":"02:00","low":0,"mid":0,"precip":0.0,"rh":74,"temp":3.1,"time":"2025-09-18T23:00Z","wind":5.5},{"cloud":0,"dark":true,"high":0,"local":"03:00","low":0,"mid":0,"precip":0.0,"rh":75,"temp":3.1,"time":"2025-09-19T00:00Z","wind":6.2},{"cloud":0,"dark":true,"high":0,"local":"04:00","low":0,"mid":0,"precip":0.0,"rh":71,"temp":3.2,"time":"2025-09-19T01:00Z","wind":7.3},{"cloud":0,"dark":true,"high":0,"local":"05:00","low":0,"mid":0,"precip":0.0,"rh":73,"temp":2.9,"time":"2025-09-19T02:00Z","wind":5.9},{"cloud":0,"dark":false,"high":0,"local":"06:00","low":0,"mid":0,"precip":0.0,"rh":77,"temp":2.3,"time":"2025-09-19T03:00Z","wind":5.4},{"cloud":0,"dark":false,"high":0,"local":"07:00","low":0,"mid":0,"precip":0.0,"rh":78,"temp":2.0,"time":"2025-09-19T04:00Z","wind":5.4},{"cloud":0,"dark":false,"high":0,"local":"08:00","low":0,"mid":0,"precip":0.0,"rh":72,"temp":3.8,"time":"2025-09-19T05:00Z","wind":6.6}],"forecast_source":"history","forecast_updated_at":"2026-10-22T23:30:32Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-09-18T17:58:58Z","dark_hours":8.54,"dark_to":"2025-09-19T02:31:27Z","moon":{"illumination":0.085,"phase":"waning crescent","waxing":false},"moon_free_dark_hours":7.43,"moonrise":"2025-09-19T01:25:43Z","moonset":"2025-09-18T14:57:10Z","sunrise":"2025-09-19T04:05:24Z","sunset":"2025-09-18T16:25:08Z","twilight":{"astronomical":{"end":"2025-09-18T17:58:58Z","start":"2025-09-19T02:31:27Z"},"civil":{"end":"2025-09-18T16:52:54Z","start":"2025-09-19T03:37:36Z"},"nautical":{"end":"2025-09-18T17:25:33Z","start":"2025-09-19T03:04:55Z"}},"window_end":"2025-09-19T09:00:00Z","window_start":"2025-09-18T09:00:00Z"},"night_date":"2025-09-18","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}