function displayDate(){
let currentTime = new Date().getTime();
let tomorrowTime = new Date().getTime()+currentTime;
if(currentTime < tomorrowTime){
alert("会☻")
}else{
alert("不会☹")
}
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<button class="lxy" type="button" onclick="displayDate()">今天会准时下班?</button>
</body>
</html>
.lxy{
height: 50px;
background-color: bisque;
border-color: bisque;
}