How to calculate the hours between two times with jquery?

html, input, javascript, jquery, time

Solution

Easy way is if you get a negative value, add 24 hours to it and you should have your result.

var hours = parseInt($(".Time2").val().split(':')[0], 10) - parseInt($(".Time1").val().split(':')[0], 10);

// if negative result, add 24 hours
if(hours < 0) hours = 24 + hours;

Demo: http://jsfiddle.net/44NCk/1/

Getting the minutes as a decimal involves a bit more as you can see in thsi fiddle: http://jsfiddle.net/44NCk/2/

function calculate() {
     var time1 = $(".Time1").val().split(':'), time2 = $(".Time2").val().split(':');
     var hours1 = parseInt(time1[0], 10), 
         hours2 = parseInt(time2[0], 10),
         mins1 = parseInt(time1[1], 10),
         mins2 = parseInt(time2[1], 10);
     var hours = hours2 - hours1, mins = 0;

     // get hours
     if(hours < 0) hours = 24 + hours;

     // get minutes
     if(mins2 >= mins1) {
         mins = mins2 - mins1;
     }
     else {
         mins = (mins2 + 60) - mins1;
         hours--;
     }

     // convert to fraction of 60
     mins = mins / 60; 

     hours += mins;
     hours = hours.toFixed(2);
     $(".Hours").val(hours);
 }

Problem

I am trying to calculate the hours between two times. Below is where I am currently but this code fails in two ways. 1). I need `.Hours` to output time in decimal. (e.g one and half hours should output 1.5 and 15mins should be 0.25). 2). Calculation currently does not treat values for time as `time`. (e.g 23:00 to 2:00 should equal `3` and NOT `-21` as currently). HTML ``` <input class="Time1" value="10:00" /> <input class="Time2" value="12:00" /> <input class="Hours" value="0" /> ``` JQUERY ``` $(function () { function calculate() { var hours = parseInt($(".Time2").val().split(':')[0], 10) - parseInt($(".Time1").val().split(':')[0], 10); $(".Hours").val(hours); } $(".Time1,.Time2").change(calculate); calculate(); }); ``` http://jsfiddle.net/44NCk/

Original source