{"assessment":{"best_window":{"end":"2025-12-11T20:00Z","end_local":"22:00","hours":3.42,"label":"good","mean_quality":0.9,"start":"2025-12-11T16:35Z","start_local":"18:35"},"cost":{"altitude":0.0,"clouds":5.0,"darkness":2.66,"moon":1.76},"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":0,"high":0,"iso":"2025-12-11T15:00Z","label":"unusable","low":0,"mid":0,"moon_alt":-42,"precip":0.0,"q":0.0,"rh":76,"sky":"civil twilight","temp":2.2,"time":"17:00","wind":0.7},{"alt":null,"cloud":0,"high":0,"iso":"2025-12-11T16:00Z","label":"marginal","low":0,"mid":0,"moon_alt":-44,"precip":0.0,"q":0.5,"rh":78,"sky":"astronomical twilight","temp":1.0,"time":"18:00","wind":2.7},{"alt":null,"cloud":0,"high":0,"iso":"2025-12-11T17:00Z","label":"good","low":0,"mid":0,"moon_alt":-44,"precip":0.0,"q":1.0,"rh":79,"sky":"night","temp":0.3,"time":"19:00","wind":4.0},{"alt":null,"cloud":9,"high":0,"iso":"2025-12-11T18:00Z","label":"good","low":0,"mid":9,"moon_alt":-39,"precip":0.0,"q":0.9,"rh":79,"sky":"night","temp":0.0,"time":"20:00","wind":4.2},{"alt":null,"cloud":23,"high":0,"iso":"2025-12-11T19:00Z","label":"good","low":0,"mid":23,"moon_alt":-32,"precip":0.0,"q":0.74,"rh":80,"sky":"night","temp":-0.3,"time":"21:00","wind":4.2},{"alt":null,"cloud":48,"high":0,"iso":"2025-12-11T20:00Z","label":"marginal","low":0,"mid":48,"moon_alt":-23,"precip":0.0,"q":0.47,"rh":81,"sky":"night","temp":-0.6,"time":"22:00","wind":3.6},{"alt":null,"cloud":100,"high":0,"iso":"2025-12-11T21:00Z","label":"unusable","low":0,"mid":100,"moon_alt":-14,"precip":0.0,"q":0.0,"rh":80,"sky":"night","temp":-0.5,"time":"23:00","wind":3.3},{"alt":null,"cloud":100,"high":0,"iso":"2025-12-11T22:00Z","label":"unusable","low":5,"mid":100,"moon_alt":-3,"precip":0.0,"q":0.0,"rh":74,"sky":"night","temp":1.0,"time":"00:00","wind":2.4},{"alt":null,"cloud":100,"high":0,"iso":"2025-12-11T23:00Z","label":"unusable","low":9,"mid":100,"moon_alt":8,"precip":0.0,"q":0.0,"rh":72,"sky":"night","temp":1.6,"time":"01:00","wind":2.7},{"alt":null,"cloud":100,"high":0,"iso":"2025-12-12T00:00Z","label":"unusable","low":10,"mid":100,"moon_alt":18,"precip":0.0,"q":0.0,"rh":75,"sky":"night","temp":1.1,"time":"02:00","wind":2.8},{"alt":null,"cloud":75,"high":0,"iso":"2025-12-12T01:00Z","label":"poor","low":8,"mid":74,"moon_alt":28,"precip":0.0,"q":0.12,"rh":73,"sky":"night","temp":1.5,"time":"03:00","wind":2.9},{"alt":null,"cloud":11,"high":0,"iso":"2025-12-12T02:00Z","label":"marginal","low":5,"mid":10,"moon_alt":37,"precip":0.0,"q":0.6,"rh":79,"sky":"night","temp":0.1,"time":"04:00","wind":2.9},{"alt":null,"cloud":12,"high":0,"iso":"2025-12-12T03:00Z","label":"marginal","low":4,"mid":12,"moon_alt":45,"precip":0.0,"q":0.58,"rh":80,"sky":"night","temp":-0.4,"time":"05:00","wind":3.8},{"alt":null,"cloud":7,"high":0,"iso":"2025-12-12T04:00Z","label":"marginal","low":2,"mid":7,"moon_alt":49,"precip":0.0,"q":0.3,"rh":80,"sky":"astronomical twilight","temp":-1.0,"time":"06:00","wind":4.0},{"alt":null,"cloud":7,"high":0,"iso":"2025-12-12T05:00Z","label":"poor","low":3,"mid":7,"moon_alt":49,"precip":0.0,"q":0.09,"rh":79,"sky":"nautical twilight","temp":-1.0,"time":"07:00","wind":4.2}],"peak_quality":1.0,"peak_sky":1.0,"quality_hours":5.41,"reasons":["cloud cover cost 5.0 quality-hours","daylight and twilight cost 2.7 quality-hours","moonlight cost 1.8 quality-hours"],"reference_hours":4.0,"score":52,"score_astronomy":100,"score_weather":52,"sky_hours":10.42,"verdict":"marginal","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2025-12-11T15:25Z","end_local":"17:25","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2025-12-11T14:50Z","start_local":"16:50"},{"end":"2025-12-11T16:00Z","end_local":"18:00","hours":0.58,"label":"poor","mean_quality":0.15,"start":"2025-12-11T15:25Z","start_local":"17:25"},{"end":"2025-12-11T16:35Z","end_local":"18:35","hours":0.58,"label":"marginal","mean_quality":0.5,"start":"2025-12-11T16:00Z","start_local":"18:00"},{"end":"2025-12-11T20:00Z","end_local":"22:00","hours":3.42,"label":"good","mean_quality":0.9,"start":"2025-12-11T16:35Z","start_local":"18:35"},{"end":"2025-12-11T21:00Z","end_local":"23:00","hours":1.0,"label":"marginal","mean_quality":0.47,"start":"2025-12-11T20:00Z","start_local":"22:00"},{"end":"2025-12-12T01:00Z","end_local":"03:00","hours":4.0,"label":"unusable","mean_quality":0.0,"start":"2025-12-11T21:00Z","start_local":"23:00"},{"end":"2025-12-12T02:00Z","end_local":"04:00","hours":1.0,"label":"poor","mean_quality":0.12,"start":"2025-12-12T01:00Z","start_local":"03:00"},{"end":"2025-12-12T04:35Z","end_local":"06:35","hours":2.58,"label":"marginal","mean_quality":0.52,"start":"2025-12-12T02:00Z","start_local":"04:00"},{"end":"2025-12-12T05:10Z","end_local":"07:10","hours":0.58,"label":"poor","mean_quality":0.09,"start":"2025-12-12T04:35Z","start_local":"06:35"},{"end":"2025-12-12T05:40Z","end_local":"07:40","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2025-12-12T05:10Z","start_local":"07:10"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":0,"dark":false,"high":0,"local":"16:00","low":0,"mid":0,"precip":0.0,"rh":71,"temp":5.4,"time":"2025-12-11T14:00Z","wind":0.8},{"cloud":0,"dark":false,"high":0,"local":"17:00","low":0,"mid":0,"precip":0.0,"rh":76,"temp":2.2,"time":"2025-12-11T15:00Z","wind":0.7},{"cloud":0,"dark":false,"high":0,"local":"18:00","low":0,"mid":0,"precip":0.0,"rh":78,"temp":1.0,"time":"2025-12-11T16:00Z","wind":2.7},{"cloud":0,"dark":true,"high":0,"local":"19:00","low":0,"mid":0,"precip":0.0,"rh":79,"temp":0.3,"time":"2025-12-11T17:00Z","wind":4.0},{"cloud":9,"dark":true,"high":0,"local":"20:00","low":0,"mid":9,"precip":0.0,"rh":79,"temp":0.0,"time":"2025-12-11T18:00Z","wind":4.2},{"cloud":23,"dark":true,"high":0,"local":"21:00","low":0,"mid":23,"precip":0.0,"rh":80,"temp":-0.3,"time":"2025-12-11T19:00Z","wind":4.2},{"cloud":48,"dark":true,"high":0,"local":"22:00","low":0,"mid":48,"precip":0.0,"rh":81,"temp":-0.6,"time":"2025-12-11T20:00Z","wind":3.6},{"cloud":100,"dark":true,"high":0,"local":"23:00","low":0,"mid":100,"precip":0.0,"rh":80,"temp":-0.5,"time":"2025-12-11T21:00Z","wind":3.3},{"cloud":100,"dark":true,"high":0,"local":"00:00","low":5,"mid":100,"precip":0.0,"rh":74,"temp":1.0,"time":"2025-12-11T22:00Z","wind":2.4},{"cloud":100,"dark":true,"high":0,"local":"01:00","low":9,"mid":100,"precip":0.0,"rh":72,"temp":1.6,"time":"2025-12-11T23:00Z","wind":2.7},{"cloud":100,"dark":true,"high":0,"local":"02:00","low":10,"mid":100,"precip":0.0,"rh":75,"temp":1.1,"time":"2025-12-12T00:00Z","wind":2.8},{"cloud":75,"dark":true,"high":0,"local":"03:00","low":8,"mid":74,"precip":0.0,"rh":73,"temp":1.5,"time":"2025-12-12T01:00Z","wind":2.9},{"cloud":11,"dark":true,"high":0,"local":"04:00","low":5,"mid":10,"precip":0.0,"rh":79,"temp":0.1,"time":"2025-12-12T02:00Z","wind":2.9},{"cloud":12,"dark":true,"high":0,"local":"05:00","low":4,"mid":12,"precip":0.0,"rh":80,"temp":-0.4,"time":"2025-12-12T03:00Z","wind":3.8},{"cloud":7,"dark":false,"high":0,"local":"06:00","low":2,"mid":7,"precip":0.0,"rh":80,"temp":-1.0,"time":"2025-12-12T04:00Z","wind":4.0},{"cloud":7,"dark":false,"high":0,"local":"07:00","low":3,"mid":7,"precip":0.0,"rh":79,"temp":-1.0,"time":"2025-12-12T05:00Z","wind":4.2},{"cloud":4,"dark":false,"high":0,"local":"08:00","low":0,"mid":4,"precip":0.0,"rh":80,"temp":-1.4,"time":"2025-12-12T06:00Z","wind":4.7}],"forecast_source":"history","forecast_updated_at":"2026-10-18T11:22:26Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-12-11T16:30:41Z","dark_hours":11.47,"dark_to":"2025-12-12T03:58:37Z","moon":{"illumination":0.494,"phase":"last quarter","waxing":false},"moon_free_dark_hours":5.77,"moonrise":"2025-12-11T22:17:47Z","moonset":"2025-12-11T10:17:53Z","sunrise":"2025-12-12T05:38:48Z","sunset":"2025-12-11T14:50:35Z","twilight":{"astronomical":{"end":"2025-12-11T16:30:41Z","start":"2025-12-12T03:58:37Z"},"civil":{"end":"2025-12-11T15:22:00Z","start":"2025-12-12T05:07:21Z"},"nautical":{"end":"2025-12-11T15:56:55Z","start":"2025-12-12T04:32:23Z"}},"window_end":"2025-12-12T10:00:00Z","window_start":"2025-12-11T10:00:00Z"},"night_date":"2025-12-11","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}