{"assessment":{"best_window":{"end":"2026-04-07T22:00Z","end_local":"01:00","hours":1.0,"label":"good","mean_quality":0.71,"start":"2026-04-07T21:00Z","start_local":"00:00"},"cost":{"altitude":0.0,"clouds":4.2,"darkness":2.59,"moon":1.33},"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":11,"high":10,"iso":"2026-04-07T17:00Z","label":"unusable","low":1,"mid":1,"moon_alt":-58,"precip":0.0,"q":0.0,"rh":65,"sky":"civil twilight","temp":4.5,"time":"20:00","wind":6.8},{"alt":null,"cloud":91,"high":91,"iso":"2026-04-07T18:00Z","label":"unusable","low":0,"mid":0,"moon_alt":-47,"precip":0.0,"q":0.0,"rh":72,"sky":"astronomical twilight","temp":3.1,"time":"21:00","wind":6.5},{"alt":null,"cloud":83,"high":82,"iso":"2026-04-07T19:00Z","label":"unusable","low":0,"mid":2,"moon_alt":-37,"precip":0.0,"q":0.0,"rh":72,"sky":"night","temp":2.7,"time":"22:00","wind":5.9},{"alt":null,"cloud":63,"high":50,"iso":"2026-04-07T20:00Z","label":"marginal","low":1,"mid":24,"moon_alt":-26,"precip":0.0,"q":0.3,"rh":78,"sky":"night","temp":1.5,"time":"23:00","wind":5.4},{"alt":null,"cloud":26,"high":6,"iso":"2026-04-07T21:00Z","label":"good","low":9,"mid":13,"moon_alt":-16,"precip":0.0,"q":0.71,"rh":78,"sky":"night","temp":1.3,"time":"00:00","wind":5.2},{"alt":null,"cloud":44,"high":0,"iso":"2026-04-07T22:00Z","label":"marginal","low":32,"mid":24,"moon_alt":-7,"precip":0.0,"q":0.51,"rh":77,"sky":"night","temp":1.6,"time":"01:00","wind":5.8},{"alt":null,"cloud":73,"high":0,"iso":"2026-04-07T23:00Z","label":"poor","low":63,"mid":41,"moon_alt":2,"precip":0.0,"q":0.13,"rh":71,"sky":"night","temp":3.2,"time":"02:00","wind":10.2},{"alt":null,"cloud":44,"high":0,"iso":"2026-04-08T00:00Z","label":"marginal","low":26,"mid":26,"moon_alt":9,"precip":0.0,"q":0.34,"rh":83,"sky":"night","temp":1.9,"time":"03:00","wind":8.6},{"alt":null,"cloud":17,"high":7,"iso":"2026-04-08T01:00Z","label":"marginal","low":1,"mid":10,"moon_alt":15,"precip":0.0,"q":0.52,"rh":78,"sky":"night","temp":2.5,"time":"04:00","wind":12.1},{"alt":null,"cloud":6,"high":5,"iso":"2026-04-08T02:00Z","label":"marginal","low":0,"mid":0,"moon_alt":18,"precip":0.0,"q":0.59,"rh":74,"sky":"night","temp":1.7,"time":"05:00","wind":15.1},{"alt":null,"cloud":0,"high":0,"iso":"2026-04-08T03:00Z","label":"poor","low":0,"mid":0,"moon_alt":19,"precip":0.0,"q":0.09,"rh":62,"sky":"nautical twilight","temp":1.1,"time":"06:00","wind":19.0}],"peak_quality":0.71,"peak_sky":1.0,"quality_hours":2.97,"reasons":["cloud cover cost 4.2 quality-hours","daylight and twilight cost 2.6 quality-hours","moonlight cost 1.3 quality-hours"],"reference_hours":4.0,"score":41,"score_astronomy":100,"score_weather":41,"sky_hours":7.17,"verdict":"marginal","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2026-04-07T17:25Z","end_local":"20:25","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2026-04-07T16:50Z","start_local":"19:50"},{"end":"2026-04-07T18:00Z","end_local":"21:00","hours":0.58,"label":"poor","mean_quality":0.13,"start":"2026-04-07T17:25Z","start_local":"20:25"},{"end":"2026-04-07T20:00Z","end_local":"23:00","hours":2.0,"label":"unusable","mean_quality":0.0,"start":"2026-04-07T18:00Z","start_local":"21:00"},{"end":"2026-04-07T21:00Z","end_local":"00:00","hours":1.0,"label":"marginal","mean_quality":0.3,"start":"2026-04-07T20:00Z","start_local":"23:00"},{"end":"2026-04-07T22:00Z","end_local":"01:00","hours":1.0,"label":"good","mean_quality":0.71,"start":"2026-04-07T21:00Z","start_local":"00:00"},{"end":"2026-04-07T23:00Z","end_local":"02:00","hours":1.0,"label":"marginal","mean_quality":0.49,"start":"2026-04-07T22:00Z","start_local":"01:00"},{"end":"2026-04-08T00:00Z","end_local":"03:00","hours":1.0,"label":"poor","mean_quality":0.13,"start":"2026-04-07T23:00Z","start_local":"02:00"},{"end":"2026-04-08T02:20Z","end_local":"05:20","hours":2.33,"label":"marginal","mean_quality":0.45,"start":"2026-04-08T00:00Z","start_local":"03:00"},{"end":"2026-04-08T03:25Z","end_local":"06:25","hours":1.08,"label":"poor","mean_quality":0.2,"start":"2026-04-08T02:20Z","start_local":"05:20"},{"end":"2026-04-08T03:55Z","end_local":"06:55","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2026-04-08T03:25Z","start_local":"06:25"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":9,"dark":false,"high":5,"local":"19:00","low":1,"mid":5,"precip":0.0,"rh":54,"temp":7.6,"time":"2026-04-07T16:00Z","wind":10.4},{"cloud":11,"dark":false,"high":10,"local":"20:00","low":1,"mid":1,"precip":0.0,"rh":65,"temp":4.5,"time":"2026-04-07T17:00Z","wind":6.8},{"cloud":91,"dark":false,"high":91,"local":"21:00","low":0,"mid":0,"precip":0.0,"rh":72,"temp":3.1,"time":"2026-04-07T18:00Z","wind":6.5},{"cloud":83,"dark":true,"high":82,"local":"22:00","low":0,"mid":2,"precip":0.0,"rh":72,"temp":2.7,"time":"2026-04-07T19:00Z","wind":5.9},{"cloud":63,"dark":true,"high":50,"local":"23:00","low":1,"mid":24,"precip":0.0,"rh":78,"temp":1.5,"time":"2026-04-07T20:00Z","wind":5.4},{"cloud":26,"dark":true,"high":6,"local":"00:00","low":9,"mid":13,"precip":0.0,"rh":78,"temp":1.3,"time":"2026-04-07T21:00Z","wind":5.2},{"cloud":44,"dark":true,"high":0,"local":"01:00","low":32,"mid":24,"precip":0.0,"rh":77,"temp":1.6,"time":"2026-04-07T22:00Z","wind":5.8},{"cloud":73,"dark":true,"high":0,"local":"02:00","low":63,"mid":41,"precip":0.0,"rh":71,"temp":3.2,"time":"2026-04-07T23:00Z","wind":10.2},{"cloud":44,"dark":true,"high":0,"local":"03:00","low":26,"mid":26,"precip":0.0,"rh":83,"temp":1.9,"time":"2026-04-08T00:00Z","wind":8.6},{"cloud":17,"dark":true,"high":7,"local":"04:00","low":1,"mid":10,"precip":0.0,"rh":78,"temp":2.5,"time":"2026-04-08T01:00Z","wind":12.1},{"cloud":6,"dark":true,"high":5,"local":"05:00","low":0,"mid":0,"precip":0.0,"rh":74,"temp":1.7,"time":"2026-04-08T02:00Z","wind":15.1},{"cloud":0,"dark":false,"high":0,"local":"06:00","low":0,"mid":0,"precip":0.0,"rh":62,"temp":1.1,"time":"2026-04-08T03:00Z","wind":19.0},{"cloud":8,"dark":false,"high":0,"local":"07:00","low":7,"mid":5,"precip":0.0,"rh":48,"temp":1.2,"time":"2026-04-08T04:00Z","wind":24.2}],"forecast_source":"history","forecast_updated_at":"2026-10-14T22:38:43Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2026-04-07T18:30:19Z","dark_hours":7.75,"dark_to":"2026-04-08T02:15:14Z","moon":{"illumination":0.71,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":4.28,"moonrise":"2026-04-07T22:48:25Z","moonset":"2026-04-08T07:01:25Z","sunrise":"2026-04-08T03:52:39Z","sunset":"2026-04-07T16:52:49Z","twilight":{"astronomical":{"end":"2026-04-07T18:30:19Z","start":"2026-04-08T02:15:14Z"},"civil":{"end":"2026-04-07T17:21:12Z","start":"2026-04-08T03:24:17Z"},"nautical":{"end":"2026-04-07T17:55:02Z","start":"2026-04-08T02:50:30Z"}},"window_end":"2026-04-08T09:00:00Z","window_start":"2026-04-07T09:00:00Z"},"night_date":"2026-04-07","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}
