{"assessment":{"best_window":{"end":"2025-09-14T00:45Z","end_local":"03:45","hours":6.58,"label":"good","mean_quality":0.72,"start":"2025-09-13T18:10Z","start_local":"21:10"},"cost":{"altitude":0.0,"clouds":0.44,"darkness":2.55,"moon":2.4},"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":33,"high":0,"iso":"2025-09-13T17:00Z","label":"unusable","low":33,"mid":1,"moon_alt":-19,"precip":0.0,"q":0.0,"rh":82,"sky":"civil twilight","temp":11.5,"time":"20:00","wind":4.8},{"alt":null,"cloud":29,"high":0,"iso":"2025-09-13T18:00Z","label":"marginal","low":29,"mid":0,"moon_alt":-13,"precip":0.0,"q":0.34,"rh":84,"sky":"astronomical twilight","temp":11.2,"time":"21:00","wind":4.8},{"alt":null,"cloud":2,"high":0,"iso":"2025-09-13T19:00Z","label":"good","low":2,"mid":0,"moon_alt":-7,"precip":0.0,"q":0.98,"rh":82,"sky":"night","temp":10.1,"time":"22:00","wind":5.3},{"alt":null,"cloud":1,"high":0,"iso":"2025-09-13T20:00Z","label":"good","low":1,"mid":0,"moon_alt":2,"precip":0.0,"q":0.76,"rh":86,"sky":"night","temp":8.3,"time":"23:00","wind":2.1},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-13T21:00Z","label":"good","low":0,"mid":0,"moon_alt":11,"precip":0.0,"q":0.73,"rh":87,"sky":"night","temp":7.8,"time":"00:00","wind":1.5},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-13T22:00Z","label":"good","low":0,"mid":0,"moon_alt":21,"precip":0.0,"q":0.7,"rh":88,"sky":"night","temp":7.3,"time":"01:00","wind":2.5},{"alt":null,"cloud":1,"high":0,"iso":"2025-09-13T23:00Z","label":"good","low":1,"mid":0,"moon_alt":31,"precip":0.0,"q":0.65,"rh":88,"sky":"night","temp":7.1,"time":"02:00","wind":2.4},{"alt":null,"cloud":1,"high":0,"iso":"2025-09-14T00:00Z","label":"good","low":1,"mid":0,"moon_alt":42,"precip":0.0,"q":0.62,"rh":88,"sky":"night","temp":6.8,"time":"03:00","wind":2.0},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-14T01:00Z","label":"marginal","low":0,"mid":0,"moon_alt":53,"precip":0.0,"q":0.6,"rh":91,"sky":"night","temp":6.1,"time":"04:00","wind":3.7},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-14T02:00Z","label":"marginal","low":0,"mid":0,"moon_alt":64,"precip":0.0,"q":0.58,"rh":92,"sky":"night","temp":5.9,"time":"05:00","wind":3.9},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-14T03:00Z","label":"poor","low":0,"mid":0,"moon_alt":73,"precip":0.0,"q":0.08,"rh":94,"sky":"nautical twilight","temp":5.7,"time":"06:00","wind":4.8},{"alt":null,"cloud":0,"high":0,"iso":"2025-09-14T04:00Z","label":"unusable","low":0,"mid":0,"moon_alt":76,"precip":0.0,"q":0.0,"rh":96,"sky":"civil twilight","temp":5.7,"time":"07:00","wind":4.6}],"peak_quality":0.98,"peak_sky":1.0,"quality_hours":6.19,"reasons":["daylight and twilight cost 2.5 quality-hours","moonlight cost 2.4 quality-hours","cloud cover cost 0.4 quality-hours"],"reference_hours":4.0,"score":93,"score_astronomy":100,"score_weather":93,"sky_hours":6.64,"verdict":"good","verdict_astronomy":"good","weather_known":true,"windows":[{"end":"2025-09-13T17:05Z","end_local":"20:05","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2025-09-13T16:30Z","start_local":"19:30"},{"end":"2025-09-13T17:35Z","end_local":"20:35","hours":0.5,"label":"poor","mean_quality":0.09,"start":"2025-09-13T17:05Z","start_local":"20:05"},{"end":"2025-09-13T18:10Z","end_local":"21:10","hours":0.58,"label":"marginal","mean_quality":0.32,"start":"2025-09-13T17:35Z","start_local":"20:35"},{"end":"2025-09-14T00:45Z","end_local":"03:45","hours":6.58,"label":"good","mean_quality":0.72,"start":"2025-09-13T18:10Z","start_local":"21:10"},{"end":"2025-09-14T02:30Z","end_local":"05:30","hours":1.75,"label":"marginal","mean_quality":0.58,"start":"2025-09-14T00:45Z","start_local":"03:45"},{"end":"2025-09-14T03:35Z","end_local":"06:35","hours":1.08,"label":"poor","mean_quality":0.18,"start":"2025-09-14T02:30Z","start_local":"05:30"},{"end":"2025-09-14T04:05Z","end_local":"07:05","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2025-09-14T03:35Z","start_local":"06:35"}]},"calculation_version":"2026-10-10.1","forecast":[{"cloud":23,"dark":false,"high":0,"local":"19:00","low":23,"mid":1,"precip":0.0,"rh":70,"temp":13.6,"time":"2025-09-13T16:00Z","wind":8.1},{"cloud":33,"dark":false,"high":0,"local":"20:00","low":33,"mid":1,"precip":0.0,"rh":82,"temp":11.5,"time":"2025-09-13T17:00Z","wind":4.8},{"cloud":29,"dark":false,"high":0,"local":"21:00","low":29,"mid":0,"precip":0.0,"rh":84,"temp":11.2,"time":"2025-09-13T18:00Z","wind":4.8},{"cloud":2,"dark":true,"high":0,"local":"22:00","low":2,"mid":0,"precip":0.0,"rh":82,"temp":10.1,"time":"2025-09-13T19:00Z","wind":5.3},{"cloud":1,"dark":true,"high":0,"local":"23:00","low":1,"mid":0,"precip":0.0,"rh":86,"temp":8.3,"time":"2025-09-13T20:00Z","wind":2.1},{"cloud":0,"dark":true,"high":0,"local":"00:00","low":0,"mid":0,"precip":0.0,"rh":87,"temp":7.8,"time":"2025-09-13T21:00Z","wind":1.5},{"cloud":0,"dark":true,"high":0,"local":"01:00","low":0,"mid":0,"precip":0.0,"rh":88,"temp":7.3,"time":"2025-09-13T22:00Z","wind":2.5},{"cloud":1,"dark":true,"high":0,"local":"02:00","low":1,"mid":0,"precip":0.0,"rh":88,"temp":7.1,"time":"2025-09-13T23:00Z","wind":2.4},{"cloud":1,"dark":true,"high":0,"local":"03:00","low":1,"mid":0,"precip":0.0,"rh":88,"temp":6.8,"time":"2025-09-14T00:00Z","wind":2.0},{"cloud":0,"dark":true,"high":0,"local":"04:00","low":0,"mid":0,"precip":0.0,"rh":91,"temp":6.1,"time":"2025-09-14T01:00Z","wind":3.7},{"cloud":0,"dark":true,"high":0,"local":"05:00","low":0,"mid":0,"precip":0.0,"rh":92,"temp":5.9,"time":"2025-09-14T02:00Z","wind":3.9},{"cloud":0,"dark":false,"high":0,"local":"06:00","low":0,"mid":0,"precip":0.0,"rh":94,"temp":5.7,"time":"2025-09-14T03:00Z","wind":4.8},{"cloud":0,"dark":false,"high":0,"local":"07:00","low":0,"mid":0,"precip":0.0,"rh":96,"temp":5.7,"time":"2025-09-14T04:00Z","wind":4.6},{"cloud":0,"dark":false,"high":0,"local":"08:00","low":0,"mid":0,"precip":0.0,"rh":90,"temp":7.6,"time":"2025-09-14T05:00Z","wind":6.8}],"forecast_source":"history","forecast_updated_at":"2026-10-22T22:48:40Z","limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2025-09-13T18:08:38Z","dark_hours":8.28,"dark_to":"2025-09-14T02:25:22Z","moon":{"illumination":0.558,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":1.67,"moonrise":"2025-09-13T19:49:14Z","moonset":"2025-09-13T10:50:24Z","sunrise":"2025-09-14T04:00:17Z","sunset":"2025-09-13T16:33:49Z","twilight":{"astronomical":{"end":"2025-09-13T18:08:38Z","start":"2025-09-14T02:25:22Z"},"civil":{"end":"2025-09-13T17:01:44Z","start":"2025-09-14T03:32:20Z"},"nautical":{"end":"2025-09-13T17:34:41Z","start":"2025-09-14T02:59:20Z"}},"window_end":"2025-09-14T09:00:00Z","window_start":"2025-09-13T09:00:00Z"},"night_date":"2025-09-13","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":[]}