function diff(date1, date2) { var diff = date2 - date1; var diffH = Math.floor((diff % 86400000) / 3600000); // 시간 var diffM = Math.floor(((diff % 86400000) % 3600000) / 60000); // 분 var diffS = Math.floor(diff / 1000 % 60); // 초 if (Math.sign(diff) === -1) { // 음수 check return '퇴근시간이 지났어요...' } else { return '퇴근시간까지: ' + [diffH < 10 ? '0' + diffH : diffH, diffM < 10 ? '0' + diffM : diffM, diffS < 10 ? '0' + diffS : diffS].join(':') + '남음 ;;' } } function solution(n) { var nowDate = new Date(); var exitDate = new Date(); // 17:30:00 var input_arr = n.split(':'); exitDate.setHours(input_arr[0]); exitDate.setMinutes(input_arr[1]); exitDate.setSeconds(input_arr[2]); console.log(diff(nowDate, exitDate)) } solution('17:00:00'); // 퇴근 시간 Document