{"assessment":{"best_window":{"end":"2027-10-19T19:30Z","end_local":"22:30","hours":2.33,"label":"good","mean_quality":0.76,"start":"2027-10-19T17:10Z","start_local":"20:10"},"cost":{"altitude":0.0,"clouds":0.0,"darkness":2.46,"moon":5.02},"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 worth it \u2014 weather unknown","hourly":[{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T16:00Z","label":"unusable","low":null,"mid":null,"moon_alt":-14,"precip":null,"q":0.0,"rh":null,"sky":"civil twilight","temp":null,"time":"19:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T17:00Z","label":"marginal","low":null,"mid":null,"moon_alt":-7,"precip":null,"q":0.5,"rh":null,"sky":"astronomical twilight","temp":null,"time":"20:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T18:00Z","label":"good","low":null,"mid":null,"moon_alt":1,"precip":null,"q":0.68,"rh":null,"sky":"night","temp":null,"time":"21:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T19:00Z","label":"good","low":null,"mid":null,"moon_alt":10,"precip":null,"q":0.63,"rh":null,"sky":"night","temp":null,"time":"22:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T20:00Z","label":"marginal","low":null,"mid":null,"moon_alt":20,"precip":null,"q":0.57,"rh":null,"sky":"night","temp":null,"time":"23:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T21:00Z","label":"marginal","low":null,"mid":null,"moon_alt":31,"precip":null,"q":0.52,"rh":null,"sky":"night","temp":null,"time":"00:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T22:00Z","label":"marginal","low":null,"mid":null,"moon_alt":42,"precip":null,"q":0.47,"rh":null,"sky":"night","temp":null,"time":"01:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-19T23:00Z","label":"marginal","low":null,"mid":null,"moon_alt":52,"precip":null,"q":0.43,"rh":null,"sky":"night","temp":null,"time":"02:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-20T00:00Z","label":"marginal","low":null,"mid":null,"moon_alt":63,"precip":null,"q":0.4,"rh":null,"sky":"night","temp":null,"time":"03:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-20T01:00Z","label":"marginal","low":null,"mid":null,"moon_alt":72,"precip":null,"q":0.38,"rh":null,"sky":"night","temp":null,"time":"04:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-20T02:00Z","label":"marginal","low":null,"mid":null,"moon_alt":75,"precip":null,"q":0.38,"rh":null,"sky":"night","temp":null,"time":"05:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-20T03:00Z","label":"marginal","low":null,"mid":null,"moon_alt":70,"precip":null,"q":0.38,"rh":null,"sky":"night","temp":null,"time":"06:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-10-20T04:00Z","label":"poor","low":null,"mid":null,"moon_alt":61,"precip":null,"q":0.06,"rh":null,"sky":"nautical twilight","temp":null,"time":"07:00","wind":null}],"peak_quality":1.0,"peak_sky":1.0,"quality_hours":5.68,"reasons":["moonlight cost 5.0 quality-hours","daylight and twilight cost 2.5 quality-hours"],"reference_hours":4.0,"score":null,"score_astronomy":100,"score_weather":null,"sky_hours":5.68,"verdict":"unknown","verdict_astronomy":"good","weather_known":false,"windows":[{"end":"2027-10-19T16:05Z","end_local":"19:05","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2027-10-19T15:30Z","start_local":"18:30"},{"end":"2027-10-19T16:35Z","end_local":"19:35","hours":0.5,"label":"poor","mean_quality":0.15,"start":"2027-10-19T16:05Z","start_local":"19:05"},{"end":"2027-10-19T17:10Z","end_local":"20:10","hours":0.58,"label":"marginal","mean_quality":0.5,"start":"2027-10-19T16:35Z","start_local":"19:35"},{"end":"2027-10-19T19:30Z","end_local":"22:30","hours":2.33,"label":"good","mean_quality":0.76,"start":"2027-10-19T17:10Z","start_local":"20:10"},{"end":"2027-10-20T03:10Z","end_local":"06:10","hours":7.67,"label":"marginal","mean_quality":0.45,"start":"2027-10-19T19:30Z","start_local":"22:30"},{"end":"2027-10-20T04:15Z","end_local":"07:15","hours":1.08,"label":"poor","mean_quality":0.12,"start":"2027-10-20T03:10Z","start_local":"06:10"},{"end":"2027-10-20T04:40Z","end_local":"07:40","hours":0.42,"label":"unusable","mean_quality":0.0,"start":"2027-10-20T04:15Z","start_local":"07:15"}]},"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":"2027-10-19T17:06:47Z","dark_hours":9.98,"dark_to":"2027-10-20T03:05:42Z","moon":{"illumination":0.795,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":0.78,"moonrise":"2027-10-19T17:54:33Z","moonset":null,"sunrise":"2027-10-20T04:38:25Z","sunset":"2027-10-19T15:34:17Z","twilight":{"astronomical":{"end":"2027-10-19T17:06:47Z","start":"2027-10-20T03:05:42Z"},"civil":{"end":"2027-10-19T16:02:24Z","start":"2027-10-20T04:10:13Z"},"nautical":{"end":"2027-10-19T16:34:40Z","start":"2027-10-20T03:37:53Z"}},"window_end":"2027-10-20T09:00:00Z","window_start":"2027-10-19T09:00:00Z"},"night_date":"2027-10-19","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."]}