{"assessment":{"best_window":{"end":"2026-11-26T17:05Z","end_local":"19:05","hours":0.5,"label":"good","mean_quality":0.62,"start":"2026-11-26T16:35Z","start_local":"18:35"},"cost":{"altitude":0.0,"clouds":0.0,"darkness":2.62,"moon":7.16},"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":"Astronomically possible, with compromises \u2014 weather unknown","hourly":[{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T15:00Z","label":"unusable","low":null,"mid":null,"moon_alt":-12,"precip":null,"q":0.0,"rh":null,"sky":"civil twilight","temp":null,"time":"17:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T16:00Z","label":"marginal","low":null,"mid":null,"moon_alt":-4,"precip":null,"q":0.5,"rh":null,"sky":"astronomical twilight","temp":null,"time":"18:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T17:00Z","label":"good","low":null,"mid":null,"moon_alt":4,"precip":null,"q":0.6,"rh":null,"sky":"night","temp":null,"time":"19:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T18:00Z","label":"marginal","low":null,"mid":null,"moon_alt":14,"precip":null,"q":0.54,"rh":null,"sky":"night","temp":null,"time":"20:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T19:00Z","label":"marginal","low":null,"mid":null,"moon_alt":24,"precip":null,"q":0.48,"rh":null,"sky":"night","temp":null,"time":"21:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T20:00Z","label":"marginal","low":null,"mid":null,"moon_alt":34,"precip":null,"q":0.42,"rh":null,"sky":"night","temp":null,"time":"22:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T21:00Z","label":"marginal","low":null,"mid":null,"moon_alt":45,"precip":null,"q":0.37,"rh":null,"sky":"night","temp":null,"time":"23:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T22:00Z","label":"marginal","low":null,"mid":null,"moon_alt":56,"precip":null,"q":0.33,"rh":null,"sky":"night","temp":null,"time":"00:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-26T23:00Z","label":"poor","low":null,"mid":null,"moon_alt":66,"precip":null,"q":0.3,"rh":null,"sky":"night","temp":null,"time":"01:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-27T00:00Z","label":"poor","low":null,"mid":null,"moon_alt":73,"precip":null,"q":0.28,"rh":null,"sky":"night","temp":null,"time":"02:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-27T01:00Z","label":"poor","low":null,"mid":null,"moon_alt":74,"precip":null,"q":0.28,"rh":null,"sky":"night","temp":null,"time":"03:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-27T02:00Z","label":"poor","low":null,"mid":null,"moon_alt":67,"precip":null,"q":0.29,"rh":null,"sky":"night","temp":null,"time":"04:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-27T03:00Z","label":"marginal","low":null,"mid":null,"moon_alt":57,"precip":null,"q":0.32,"rh":null,"sky":"night","temp":null,"time":"05:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-27T04:00Z","label":"poor","low":null,"mid":null,"moon_alt":47,"precip":null,"q":0.18,"rh":null,"sky":"astronomical twilight","temp":null,"time":"06:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-11-27T05:00Z","label":"unusable","low":null,"mid":null,"moon_alt":36,"precip":null,"q":0.0,"rh":null,"sky":"civil twilight","temp":null,"time":"07:00","wind":null}],"peak_quality":0.63,"peak_sky":0.63,"quality_hours":4.8,"reasons":["moonlight cost 7.2 quality-hours","daylight and twilight cost 2.6 quality-hours"],"reference_hours":4.0,"score":null,"score_astronomy":63,"score_weather":null,"sky_hours":4.8,"verdict":"unknown","verdict_astronomy":"marginal","weather_known":false,"windows":[{"end":"2026-11-26T15:25Z","end_local":"17:25","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2026-11-26T14:50Z","start_local":"16:50"},{"end":"2026-11-26T16:00Z","end_local":"18:00","hours":0.58,"label":"poor","mean_quality":0.15,"start":"2026-11-26T15:25Z","start_local":"17:25"},{"end":"2026-11-26T16:35Z","end_local":"18:35","hours":0.58,"label":"marginal","mean_quality":0.5,"start":"2026-11-26T16:00Z","start_local":"18:00"},{"end":"2026-11-26T17:05Z","end_local":"19:05","hours":0.5,"label":"good","mean_quality":0.62,"start":"2026-11-26T16:35Z","start_local":"18:35"},{"end":"2026-11-26T22:50Z","end_local":"00:50","hours":5.75,"label":"marginal","mean_quality":0.44,"start":"2026-11-26T17:05Z","start_local":"19:05"},{"end":"2026-11-27T02:20Z","end_local":"04:20","hours":3.5,"label":"poor","mean_quality":0.28,"start":"2026-11-26T22:50Z","start_local":"00:50"},{"end":"2026-11-27T03:50Z","end_local":"05:50","hours":1.5,"label":"marginal","mean_quality":0.32,"start":"2026-11-27T02:20Z","start_local":"04:20"},{"end":"2026-11-27T04:55Z","end_local":"06:55","hours":1.08,"label":"poor","mean_quality":0.12,"start":"2026-11-27T03:50Z","start_local":"05:50"},{"end":"2026-11-27T05:25Z","end_local":"07:25","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2026-11-27T04:55Z","start_local":"06:55"}]},"calculation_version":"2026-10-10.1","forecast":[],"forecast_source":"none","forecast_updated_at":null,"limits":{"good_alt":30.0,"usable_alt":20.0},"night":{"dark_from":"2026-11-26T16:31:34Z","dark_hours":11.23,"dark_to":"2026-11-27T03:45:40Z","moon":{"illumination":0.921,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":0.0,"moonrise":"2026-11-26T16:32:11Z","moonset":"2026-11-27T08:32:09Z","sunrise":"2026-11-27T05:24:01Z","sunset":"2026-11-26T14:53:24Z","twilight":{"astronomical":{"end":"2026-11-26T16:31:34Z","start":"2026-11-27T03:45:40Z"},"civil":{"end":"2026-11-26T15:24:02Z","start":"2026-11-27T04:53:19Z"},"nautical":{"end":"2026-11-26T15:58:17Z","start":"2026-11-27T04:18:59Z"}},"window_end":"2026-11-27T10:00:00Z","window_start":"2026-11-26T10:00:00Z"},"night_date":"2026-11-26","site":{"elev_m":1750,"lat":41.693,"lon":24.739,"name":"NAO Rozhen"},"warnings":["No cloud data for this night (beyond the 4-day forecast, or not yet in the archive) \u2014 the score is geometry only."]}