layui ri laydate的常规使用，并且日期最大不能超过当前日期

<input  id="birthDate" name="birthDate" class="form-control" >

<script>
    layui.use(‘laydate‘, function(){
        var laydate = layui.laydate;
 
        //执行一个laydate实例
        laydate.render({
            elem: ‘#birthDate‘, //指定元素
            max: getNowFormatDate()
        });
    });
 
    function getNowFormatDate() {
        var date = new Date();
        var seperator1 = "-";
        var seperator2 = ":";
        var month = date.getMonth() + 1;
        var strDate = date.getDate();
        if (month >= 1 && month <= 9) {
            month = "0" + month;
        }
        if (strDate >= 0 && strDate <= 9) {
            strDate = "0" + strDate;
        }
        var currentdate = date.getFullYear() + seperator1 + month + seperator1 + strDate
            + " " + date.getHours() + seperator2 + date.getMinutes()
            + seperator2 + date.getSeconds();
        return currentdate;
    }
</script>