Javascript-在特定日期显示警报框

Question

我想显示一个仅在特定日期显示的警报框。

<script>
  alert('Registration Time is Over !!!');
</script>

我该怎么做？

Answer 1

<script>
var alertdate = "12/18/2018";
var alerttext = "Registration time is over!";
var d = new Date();
var today = new Date();
var dd = today.getDate();
var mm = today.getMonth()+1; 
var yyyy = today.getFullYear();

if(dd<10) {
    dd = '0'+dd
} 

if(mm<10) {
    mm = '0'+mm
} 

today = mm + '/' + dd + '/' + yyyy;
if(today == alertdate){
alert(alerttext)
}
</script>

将警报日期更改为以下格式的日期： 月日年 将Alerttext更改为所需的文本。

Answer 2

使用超时。

var currentDateMillis = new Date().getTime(); // Get time on millis
var alarmDateMillis = new Date(year, month, day, hours, minutes, seconds, milliseconds).getTime();

if (alarmDateMillis > currentDateMillis)
   setTimeout (alarm, alarmDateMillis - currentDate);
else // This is in case you want it to be shown even after the date
   alarm();

function alarm () {
   alert('Registration Time is Over !!!');
}