{"assessment":{"best_window":{"end":"2027-03-21T02:55Z","end_local":"04:55","hours":5.25,"label":"marginal","mean_quality":0.4,"start":"2027-03-20T21:40Z","start_local":"23:40"},"cost":{"altitude":0.0,"clouds":0.0,"darkness":2.46,"moon":5.86},"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":"2027-03-20T17:00Z","label":"unusable","low":null,"mid":null,"moon_alt":26,"precip":null,"q":0.0,"rh":null,"sky":"civil twilight","temp":null,"time":"19:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-20T18:00Z","label":"poor","low":null,"mid":null,"moon_alt":36,"precip":null,"q":0.19,"rh":null,"sky":"astronomical twilight","temp":null,"time":"20:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-20T19:00Z","label":"marginal","low":null,"mid":null,"moon_alt":45,"precip":null,"q":0.34,"rh":null,"sky":"night","temp":null,"time":"21:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-20T20:00Z","label":"marginal","low":null,"mid":null,"moon_alt":51,"precip":null,"q":0.31,"rh":null,"sky":"night","temp":null,"time":"22:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-20T21:00Z","label":"poor","low":null,"mid":null,"moon_alt":54,"precip":null,"q":0.3,"rh":null,"sky":"night","temp":null,"time":"23:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-20T22:00Z","label":"marginal","low":null,"mid":null,"moon_alt":52,"precip":null,"q":0.3,"rh":null,"sky":"night","temp":null,"time":"00:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-20T23:00Z","label":"marginal","low":null,"mid":null,"moon_alt":46,"precip":null,"q":0.33,"rh":null,"sky":"night","temp":null,"time":"01:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-21T00:00Z","label":"marginal","low":null,"mid":null,"moon_alt":38,"precip":null,"q":0.37,"rh":null,"sky":"night","temp":null,"time":"02:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-21T01:00Z","label":"marginal","low":null,"mid":null,"moon_alt":28,"precip":null,"q":0.43,"rh":null,"sky":"night","temp":null,"time":"03:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-21T02:00Z","label":"marginal","low":null,"mid":null,"moon_alt":17,"precip":null,"q":0.5,"rh":null,"sky":"night","temp":null,"time":"04:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-21T03:00Z","label":"poor","low":null,"mid":null,"moon_alt":6,"precip":null,"q":0.29,"rh":null,"sky":"astronomical twilight","temp":null,"time":"05:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-03-21T04:00Z","label":"unusable","low":null,"mid":null,"moon_alt":-5,"precip":null,"q":0.0,"rh":null,"sky":"civil twilight","temp":null,"time":"06:00","wind":null}],"peak_quality":0.56,"peak_sky":0.56,"quality_hours":3.6,"reasons":["moonlight cost 5.9 quality-hours","daylight and twilight cost 2.5 quality-hours"],"reference_hours":4.0,"score":null,"score_astronomy":50,"score_weather":null,"sky_hours":3.6,"verdict":"unknown","verdict_astronomy":"marginal","weather_known":false,"windows":[{"end":"2027-03-20T17:05Z","end_local":"19:05","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2027-03-20T16:30Z","start_local":"18:30"},{"end":"2027-03-20T18:10Z","end_local":"20:10","hours":1.08,"label":"poor","mean_quality":0.13,"start":"2027-03-20T17:05Z","start_local":"19:05"},{"end":"2027-03-20T20:35Z","end_local":"22:35","hours":2.42,"label":"marginal","mean_quality":0.33,"start":"2027-03-20T18:10Z","start_local":"20:10"},{"end":"2027-03-20T21:40Z","end_local":"23:40","hours":1.08,"label":"poor","mean_quality":0.3,"start":"2027-03-20T20:35Z","start_local":"22:35"},{"end":"2027-03-21T02:55Z","end_local":"04:55","hours":5.25,"label":"marginal","mean_quality":0.4,"start":"2027-03-20T21:40Z","start_local":"23:40"},{"end":"2027-03-21T04:00Z","end_local":"06:00","hours":1.08,"label":"poor","mean_quality":0.21,"start":"2027-03-21T02:55Z","start_local":"04:55"},{"end":"2027-03-21T04:25Z","end_local":"06:25","hours":0.42,"label":"unusable","mean_quality":0.0,"start":"2027-03-21T04:00Z","start_local":"06:00"}]},"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":"2027-03-20T18:06:08Z","dark_hours":8.73,"dark_to":"2027-03-21T02:50:12Z","moon":{"illumination":0.97,"phase":"waxing gibbous","waxing":true},"moon_free_dark_hours":0.0,"moonrise":"2027-03-20T14:32:11Z","moonset":"2027-03-21T03:33:04Z","sunrise":"2027-03-21T04:23:27Z","sunset":"2027-03-20T16:32:45Z","twilight":{"astronomical":{"end":"2027-03-20T18:06:08Z","start":"2027-03-21T02:50:12Z"},"civil":{"end":"2027-03-20T17:00:30Z","start":"2027-03-21T03:55:45Z"},"nautical":{"end":"2027-03-20T17:33:00Z","start":"2027-03-21T03:23:18Z"}},"window_end":"2027-03-21T10:00:00Z","window_start":"2027-03-20T10:00:00Z"},"night_date":"2027-03-20","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."]}
