Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
평균시는 지구의 자전 주기를 기준으로 계산됩니다.Pyeonggyun-si-neun jiguu-ui jajeon jugireul gijun-euro gyeseon-doemnida.Mean solar time is calculated based on the Earth's rotation period.