SOURCE

console 命令行工具 X clear

                    
>
console
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;
}