{"assessment":{"best_window":{"end":"2028-01-11T04:10Z","end_local":"06:10","hours":4.08,"label":"marginal","mean_quality":0.42,"start":"2028-01-11T00:05Z","start_local":"02:05"},"cost":{"altitude":0.0,"clouds":0.0,"darkness":2.67,"moon":8.03},"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":"2028-01-10T16:00Z","label":"poor","low":null,"mid":null,"moon_alt":27,"precip":null,"q":0.06,"rh":null,"sky":"nautical twilight","temp":null,"time":"18:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-10T17:00Z","label":"marginal","low":null,"mid":null,"moon_alt":38,"precip":null,"q":0.37,"rh":null,"sky":"night","temp":null,"time":"19:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-10T18:00Z","label":"marginal","low":null,"mid":null,"moon_alt":49,"precip":null,"q":0.31,"rh":null,"sky":"night","temp":null,"time":"20:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-10T19:00Z","label":"poor","low":null,"mid":null,"moon_alt":59,"precip":null,"q":0.27,"rh":null,"sky":"night","temp":null,"time":"21:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-10T20:00Z","label":"poor","low":null,"mid":null,"moon_alt":69,"precip":null,"q":0.24,"rh":null,"sky":"night","temp":null,"time":"22:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-10T21:00Z","label":"poor","low":null,"mid":null,"moon_alt":74,"precip":null,"q":0.23,"rh":null,"sky":"night","temp":null,"time":"23:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-10T22:00Z","label":"poor","low":null,"mid":null,"moon_alt":71,"precip":null,"q":0.24,"rh":null,"sky":"night","temp":null,"time":"00:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-10T23:00Z","label":"poor","low":null,"mid":null,"moon_alt":63,"precip":null,"q":0.26,"rh":null,"sky":"night","temp":null,"time":"01:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-11T00:00Z","label":"poor","low":null,"mid":null,"moon_alt":53,"precip":null,"q":0.3,"rh":null,"sky":"night","temp":null,"time":"02:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-11T01:00Z","label":"marginal","low":null,"mid":null,"moon_alt":42,"precip":null,"q":0.35,"rh":null,"sky":"night","temp":null,"time":"03:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-11T02:00Z","label":"marginal","low":null,"mid":null,"moon_alt":31,"precip":null,"q":0.41,"rh":null,"sky":"night","temp":null,"time":"04:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-11T03:00Z","label":"marginal","low":null,"mid":null,"moon_alt":21,"precip":null,"q":0.47,"rh":null,"sky":"night","temp":null,"time":"05:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-11T04:00Z","label":"marginal","low":null,"mid":null,"moon_alt":10,"precip":null,"q":0.54,"rh":null,"sky":"night","temp":null,"time":"06:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2028-01-11T05:00Z","label":"poor","low":null,"mid":null,"moon_alt":1,"precip":null,"q":0.09,"rh":null,"sky":"nautical twilight","temp":null,"time":"07:00","wind":null}],"peak_quality":0.54,"peak_sky":0.54,"quality_hours":4.05,"reasons":["moonlight cost 8.0 quality-hours","daylight and twilight cost 2.7 quality-hours"],"reference_hours":4.0,"score":null,"score_astronomy":54,"score_weather":null,"sky_hours":4.05,"verdict":"unknown","verdict_astronomy":"marginal","weather_known":false,"windows":[{"end":"2028-01-10T15:45Z","end_local":"17:45","hours":0.67,"label":"unusable","mean_quality":0.0,"start":"2028-01-10T15:05Z","start_local":"17:05"},{"end":"2028-01-10T16:50Z","end_local":"18:50","hours":1.08,"label":"poor","mean_quality":0.14,"start":"2028-01-10T15:45Z","start_local":"17:45"},{"end":"2028-01-10T18:20Z","end_local":"20:20","hours":1.5,"label":"marginal","mean_quality":0.34,"start":"2028-01-10T16:50Z","start_local":"18:50"},{"end":"2028-01-11T00:05Z","end_local":"02:05","hours":5.75,"label":"poor","mean_quality":0.26,"start":"2028-01-10T18:20Z","start_local":"20:20"},{"end":"2028-01-11T04:10Z","end_local":"06:10","hours":4.08,"label":"marginal","mean_quality":0.42,"start":"2028-01-11T00:05Z","start_local":"02:05"},{"end":"2028-01-11T05:20Z","end_local":"07:20","hours":1.17,"label":"poor","mean_quality":0.19,"start":"2028-01-11T04:10Z","start_local":"06:10"},{"end":"2028-01-11T05:50Z","end_local":"07:50","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2028-01-11T05:20Z","start_local":"07:20"}]},"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":"2028-01-10T16:48:27Z","dark_hours":11.33,"dark_to":"2028-01-11T04:08:24Z","moon":{"illumination":0.978,"phase":"full moon","waxing":true},"moon_free_dark_hours":0.0,"moonrise":"2028-01-10T13:13:41Z","moonset":"2028-01-11T05:05:33Z","sunrise":"2028-01-11T05:47:21Z","sunset":"2028-01-10T15:09:21Z","twilight":{"astronomical":{"end":"2028-01-10T16:48:27Z","start":"2028-01-11T04:08:24Z"},"civil":{"end":"2028-01-10T15:40:22Z","start":"2028-01-11T05:16:24Z"},"nautical":{"end":"2028-01-10T16:14:57Z","start":"2028-01-11T04:41:52Z"}},"window_end":"2028-01-11T10:00:00Z","window_start":"2028-01-10T10:00:00Z"},"night_date":"2028-01-10","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."]}