在某个时间显示div，当月份发生变化时重置

Question

我有一个div/tab设置为在今年2月1日之后显示。这很有效，直到这个月结束，然后div再次被隐藏。我希望div永远保持打开状态。第一个选项卡设置为在2月1日显示，第二个选项卡设置为在14日显示。这是我的代码。

<style>

.disable-1, .disable-2 {
  display: none;
}

.enabled {
 display: block;
}

</style>

<ul class="tabs">
    <!-- THIS UL CREATES THE TABS == Just add/remove LIs as neeed to create them. Be sure the IDs of the sections match -->
    <li><a href="#PLY-EC-001-1">Tab 1</a></li>
    <li class="disable-1"><a href="">Tab 2</a></li>
    <li class="disable-2"><a href="">Tab 3</a></li>
    <
</ul>

<script>
    // get current date on page load
    var date = new Date();

    // ask for specific date
    if (date.getFullYear() >= 2020 && date.getMonth() >= 1 && date.getDate() >= 1) {
        // get first dom-element with that class 
        var li = document.getElementsByClassName('disable-1'); 

        // if dom-element exists
        if (li.length > 0) {

            // set classname
            li[0].className = 'enabled';
        }           
    }

    if (date.getFullYear() >= 2020 && date.getMonth() >= 1 && date.getDate() >= 14) {
        // get first dom-element with that class 
        var li = document.getElementsByClassName('disable-2'); 

        // if dom-element exists
        if (li.length > 0) {

            // set classname
            li[0].className = 'enabled';
        }           
    }

</script>

Answer 1

不需要通过逻辑AND检查年、月和当前日期，只需检查当前日期是否大于特定的时间戳(在您的示例中为2020-02-01:00:00:00)：

var date = new Date();
var refd = new Date(2020,1,1,0,0,0); // <-- Reference date

// compare if now (date) is bigger than reference (refd)
// by comparing the milliseconds since 1970-01-01
if (Number(date) >= Number(refd)) // <-- compare
{
    // ... elided, as before
}

Answer 2

<script type="text/javascript">

function displayDiv()
{
   var d = new Date();
   var strDate =  d.getDate();

   if(strDate == '1')
     document.getElementById('HelloWorld').visible= true;
}
</script>


<form onLoad="displayDiv()" method="GET">
<div id="HelloWorld" style="display:none;"></div>
</form>