How to make operations with Dates/Hours in Javascript?

Question

I have to subtract two hours passed by the user in the format \'HH: MM\' and the result has to divide by the number of feeds on the day and set the exact hours that it should fe

Answer 1

You simply cannot pass hours, you have to pass Date to know which one is larger than other.

 function diff_hours(dt2, dt1) 
 {

  var diff =(dt2.getTime() - dt1.getTime()) / 1000;
  diff /= (60 * 60);
  return Math.abs(Math.round(diff));

 }
var amount_of_meal = 8;
dt1 = new Date(2014,10,2);
dt2 = new Date(2014,10,3);
var result = (diff_hours(dt1, dt2))/amount_of_meal;


dt1 = new Date("October 13, 2014 08:11:00");
dt2 = new Date("October 13, 2014 11:13:00");
console.log(diff_hours(dt1, dt2));