{"assessment":{"best_window":{"end":"2026-12-26T18:50Z","end_local":"20:50","hours":2.17,"label":"good","mean_quality":0.87,"start":"2026-12-26T16:40Z","start_local":"18:40"},"cost":{"altitude":0.0,"clouds":0.0,"darkness":2.66,"moon":6.04},"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":"2026-12-26T15:00Z","label":"unusable","low":null,"mid":null,"moon_alt":-24,"precip":null,"q":0.0,"rh":null,"sky":"civil twilight","temp":null,"time":"17:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T16:00Z","label":"poor","low":null,"mid":null,"moon_alt":-18,"precip":null,"q":0.15,"rh":null,"sky":"nautical twilight","temp":null,"time":"18:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T17:00Z","label":"good","low":null,"mid":null,"moon_alt":-10,"precip":null,"q":1.0,"rh":null,"sky":"night","temp":null,"time":"19:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T18:00Z","label":"good","low":null,"mid":null,"moon_alt":0,"precip":null,"q":1.0,"rh":null,"sky":"night","temp":null,"time":"20:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T19:00Z","label":"marginal","low":null,"mid":null,"moon_alt":10,"precip":null,"q":0.59,"rh":null,"sky":"night","temp":null,"time":"21:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T20:00Z","label":"marginal","low":null,"mid":null,"moon_alt":20,"precip":null,"q":0.53,"rh":null,"sky":"night","temp":null,"time":"22:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T21:00Z","label":"marginal","low":null,"mid":null,"moon_alt":31,"precip":null,"q":0.47,"rh":null,"sky":"night","temp":null,"time":"23:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T22:00Z","label":"marginal","low":null,"mid":null,"moon_alt":41,"precip":null,"q":0.41,"rh":null,"sky":"night","temp":null,"time":"00:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-26T23:00Z","label":"marginal","low":null,"mid":null,"moon_alt":51,"precip":null,"q":0.37,"rh":null,"sky":"night","temp":null,"time":"01:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-27T00:00Z","label":"marginal","low":null,"mid":null,"moon_alt":59,"precip":null,"q":0.34,"rh":null,"sky":"night","temp":null,"time":"02:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-27T01:00Z","label":"marginal","low":null,"mid":null,"moon_alt":64,"precip":null,"q":0.33,"rh":null,"sky":"night","temp":null,"time":"03:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-27T02:00Z","label":"marginal","low":null,"mid":null,"moon_alt":62,"precip":null,"q":0.34,"rh":null,"sky":"night","temp":null,"time":"04:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-27T03:00Z","label":"marginal","low":null,"mid":null,"moon_alt":56,"precip":null,"q":0.36,"rh":null,"sky":"night","temp":null,"time":"05:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-27T04:00Z","label":"marginal","low":null,"mid":null,"moon_alt":47,"precip":null,"q":0.39,"rh":null,"sky":"night","temp":null,"time":"06:00","wind":null},{"alt":null,"cloud":null,"high":null,"iso":"2026-12-27T05:00Z","label":"poor","low":null,"mid":null,"moon_alt":36,"precip":null,"q":0.07,"rh":null,"sky":"nautical twilight","temp":null,"time":"07:00","wind":null}],"peak_quality":1.0,"peak_sky":1.0,"quality_hours":6.22,"reasons":["moonlight cost 6.0 quality-hours","daylight and twilight cost 2.7 quality-hours"],"reference_hours":4.0,"score":null,"score_astronomy":100,"score_weather":null,"sky_hours":6.22,"verdict":"unknown","verdict_astronomy":"good","weather_known":false,"windows":[{"end":"2026-12-26T15:30Z","end_local":"17:30","hours":0.58,"label":"unusable","mean_quality":0.0,"start":"2026-12-26T14:55Z","start_local":"16:55"},{"end":"2026-12-26T16:05Z","end_local":"18:05","hours":0.58,"label":"poor","mean_quality":0.15,"start":"2026-12-26T15:30Z","start_local":"17:30"},{"end":"2026-12-26T16:40Z","end_local":"18:40","hours":0.58,"label":"marginal","mean_quality":0.5,"start":"2026-12-26T16:05Z","start_local":"18:05"},{"end":"2026-12-26T18:50Z","end_local":"20:50","hours":2.17,"label":"good","mean_quality":0.87,"start":"2026-12-26T16:40Z","start_local":"18:40"},{"end":"2026-12-27T04:10Z","end_local":"06:10","hours":9.33,"label":"marginal","mean_quality":0.41,"start":"2026-12-26T18:50Z","start_local":"20:50"},{"end":"2026-12-27T05:20Z","end_local":"07:20","hours":1.17,"label":"poor","mean_quality":0.14,"start":"2026-12-27T04:10Z","start_local":"06:10"},{"end":"2026-12-27T05:50Z","end_local":"07:50","hours":0.5,"label":"unusable","mean_quality":0.0,"start":"2026-12-27T05:20Z","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":"2026-12-26T16:36:53Z","dark_hours":11.5,"dark_to":"2026-12-27T04:06:40Z","moon":{"illumination":0.881,"phase":"waning gibbous","waxing":false},"moon_free_dark_hours":1.42,"moonrise":"2026-12-26T18:02:50Z","moonset":"2026-12-27T08:20:13Z","sunrise":"2026-12-27T05:47:04Z","sunset":"2026-12-26T14:56:26Z","twilight":{"astronomical":{"end":"2026-12-26T16:36:53Z","start":"2026-12-27T04:06:40Z"},"civil":{"end":"2026-12-26T15:28:00Z","start":"2026-12-27T05:15:32Z"},"nautical":{"end":"2026-12-26T16:03:03Z","start":"2026-12-27T04:40:30Z"}},"window_end":"2026-12-27T10:00:00Z","window_start":"2026-12-26T10:00:00Z"},"night_date":"2026-12-26","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."]}
