How to add 2 hour to time string with jquery?-CodePudding

I have two datetime-local input star time is for user changeable and the other one is read-only and I want to update that field by jquery.

<input  type="datetime-local" name="deliveryTime" id="DeliveryTime" required>

<input  type="datetime-local" name="deliveryTimeEnd" id="DeliveryTimeEnd" readonly>

$("#DeliveryTime").on("change", function() {
           var startTime = $("#DeliveryTime").val();
            startTime.setHours(startTime.getHours() 2);
            alert(startTime);
            $("#DeliveryTimeEnd").val(startTime);
            
        });

CodePudding user response：

first chnage the startTime in datetime format like below code and then get the hours

var dt = new Date(startTime);
dt.setHours(dt.getHours()   2);

Complete code is:

 $("#DeliveryTime").on("change", function() {
    var startTime = $("#DeliveryTime").val();
    alert(startTime);
    var dt = new Date(startTime);
    dt.setHours(dt.getHours()   2);
    alert(dt.toLocaleString("sv-SE"));
    $("#DeliveryTimeEnd").val(dt.toLocaleString("sv-SE"))
  });

CodePudding user response：

In the end it was not quite as trivial as I assumed in the beginning. Here is a snippet that sets the second datetime input to a time 2 hours after the time of the first input:

Date.prototype.add=function(n,unit){ this["set" unit]( this["get" unit]() n); return this;}
abc.time1.addEventListener("input",ev=>{
 const dt=new Date(abc.time1.value);
 dt.setMinutes(dt.getMinutes()-dt.getTimezoneOffset() 120);
 abc.time2.value=dt.toISOString().slice(0,-5);
});

<form name="abc">
<input  type="datetime-local" name="time1"><br>
<input  type="datetime-local" name="time2">
</form>