{"assessment":{"best_window":{"end":"2027-01-26T22:35Z","end_local":"00:35","hours":5.5,"label":"good","mean_quality":0.88,"start":"2027-01-26T17:05Z","start_local":"19:05"},"cost":{"altitude":0.0,"clouds":0.0,"darkness":2.58,"moon":3.42},"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":"2027-01-26T16:00Z","label":"poor","low":null,"mid":null,"moon_alt":-45,"precip":null,"q":0.15,"rh":null,"sky":"nautical twilight","temp":null,"time":"18:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-26T17:00Z","label":"marginal","low":null,"mid":null,"moon_alt":-37,"precip":null,"q":0.5,"rh":null,"sky":"astronomical twilight","temp":null,"time":"19:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-26T18:00Z","label":"good","low":null,"mid":null,"moon_alt":-27,"precip":null,"q":1.0,"rh":null,"sky":"night","temp":null,"time":"20:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-26T19:00Z","label":"good","low":null,"mid":null,"moon_alt":-17,"precip":null,"q":1.0,"rh":null,"sky":"night","temp":null,"time":"21:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-26T20:00Z","label":"good","low":null,"mid":null,"moon_alt":-6,"precip":null,"q":1.0,"rh":null,"sky":"night","temp":null,"time":"22:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-26T21:00Z","label":"good","low":null,"mid":null,"moon_alt":4,"precip":null,"q":0.68,"rh":null,"sky":"night","temp":null,"time":"23:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-26T22:00Z","label":"good","low":null,"mid":null,"moon_alt":14,"precip":null,"q":0.63,"rh":null,"sky":"night","temp":null,"time":"00:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-26T23:00Z","label":"marginal","low":null,"mid":null,"moon_alt":24,"precip":null,"q":0.58,"rh":null,"sky":"night","temp":null,"time":"01:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-27T00:00Z","label":"marginal","low":null,"mid":null,"moon_alt":32,"precip":null,"q":0.54,"rh":null,"sky":"night","temp":null,"time":"02:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-27T01:00Z","label":"marginal","low":null,"mid":null,"moon_alt":38,"precip":null,"q":0.52,"rh":null,"sky":"night","temp":null,"time":"03:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-27T02:00Z","label":"marginal","low":null,"mid":null,"moon_alt":40,"precip":null,"q":0.5,"rh":null,"sky":"night","temp":null,"time":"04:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-27T03:00Z","label":"marginal","low":null,"mid":null,"moon_alt":40,"precip":null,"q":0.51,"rh":null,"sky":"night","temp":null,"time":"05:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-27T04:00Z","label":"marginal","low":null,"mid":null,"moon_alt":35,"precip":null,"q":0.53,"rh":null,"sky":"night","temp":null,"time":"06:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2027-01-27T05:00Z","label":"poor","low":null,"mid":null,"moon_alt":29,"precip":null,"q":0.08,"rh":null,"sky":"nautical twilight","temp":null,"time":"07:00","wind":null}],"peak_quality":1.0,"peak_sky":1.0,"quality_hours":8.25,"reasons":["moonlight cost 3.4 quality-hours","daylight and twilight cost 2.6 quality-hours"],"reference_hours":4.0,"score":null,"score_astronomy":100,"score_weather":null,"sky_hours":8.25,"verdict":"unknown","verdict_astronomy":"good","weather_known":false,"windows":[{"end":"2027-01-26T16:00Z","end_local":"18:00","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2027-01-26T15:25Z","start_local":"17:25"},{"end":"2027-01-26T16:35Z","end_local":"18:35","hours":0.58,"label":"poor","mean_quality":0.15,"start":"2027-01-26T16:00Z","start_local":"18:00"},{"end":"2027-01-26T17:05Z","end_local":"19:05","hours":0.5,"label":"marginal","mean_quality":0.5,"start":"2027-01-26T16:35Z","start_local":"18:35"},{"end":"2027-01-26T22:35Z","end_local":"00:35","hours":5.5,"label":"good","mean_quality":0.88,"start":"2027-01-26T17:05Z","start_local":"19:05"},{"end":"2027-01-27T04:05Z","end_local":"06:05","hours":5.5,"label":"marginal","mean_quality":0.53,"start":"2027-01-26T22:35Z","start_local":"00:35"},{"end":"2027-01-27T05:10Z","end_local":"07:10","hours":1.08,"label":"poor","mean_quality":0.17,"start":"2027-01-27T04:05Z","start_local":"06:05"},{"end":"2027-01-27T05:40Z","end_local":"07:40","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2027-01-27T05:10Z","start_local":"07:10"}]},"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":"2027-01-26T17:04:53Z","dark_hours":10.95,"dark_to":"2027-01-27T04:01:57Z","moon":{"illumination":0.751,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":3.52,"moonrise":"2027-01-26T20:36:58Z","moonset":"2027-01-27T07:56:01Z","sunrise":"2027-01-27T05:38:10Z","sunset":"2027-01-26T15:28:26Z","twilight":{"astronomical":{"end":"2027-01-26T17:04:53Z","start":"2027-01-27T04:01:57Z"},"civil":{"end":"2027-01-26T15:58:21Z","start":"2027-01-27T05:08:20Z"},"nautical":{"end":"2027-01-26T16:32:00Z","start":"2027-01-27T04:34:46Z"}},"window_end":"2027-01-27T10:00:00Z","window_start":"2027-01-26T10:00:00Z"},"night_date":"2027-01-26","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."]}