calculate days between dates

Question

I'm trying to calculate the days between 2 dates but just keep getting "NaN. I've looked at other posts but can't quite work it out :-S

function checkdate() {

var currentTime = new Date()
var month = currentTime.getMonth() + 1
var day = currentTime.getDate()
var year = currentTime.getFullYear()
var datenow = (day + "/" + month + "/" + year)  


var startdate = document.forms[0].datescopestart.value;
var sDate = new Date(Date.parse("startdate","dd/mm/yy"));

var totaldays = Date.datenow - Date.sDate;  
    alert(totaldays);
    }

Duplication of http://stackoverflow.com/questions/7763327/how-to-calculate-date-difference-in-javascript — Lee Taylor, Jul 23 '12 at 16:37
This has been asked a few times on stackoverflow - http://stackoverflow.com/search?q=javascript+days+between+two+dates — Ben Pearson, Jul 23 '12 at 16:54

Mark Pieszak - Trilon.io · Answer 1 · 2013-03-13T20:01:32.923

3

Here's the function I've had in my library for a while now, works great.

function days_between(date1, date2) {

  // The number of milliseconds in one day
  var ONE_DAY = 1000 * 60 * 60 * 24

  // Convert both dates to milliseconds
  var date1_ms = date1.getTime()
  var date2_ms = date2.getTime()

  // Calculate the difference in milliseconds
  var difference_ms = Math.abs(date1_ms - date2_ms)

  // Convert back to days and return
  return Math.round(difference_ms/ONE_DAY)

}

edited Mar 13 '13 at 20:01

answered Jul 23 '12 at 16:37

Mark Pieszak - Trilon.io

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But what about leap seconds? :O – cdhowie Jul 23 '12 at 16:42

score 1 · Answer 2 · answered Jul 23 '12 at 16:36

1

Remove the quotes around startdate in the call to Date.parse. And the Date. in front of your variable names in the calculation.

answered Jul 23 '12 at 16:36

Lars Kotthoff

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score 0 · Answer 3 · answered Jul 23 '12 at 16:38

0

The easiest way to do this is as follows:

var days = Math.floor(enddate.getTime()-startdate.getTime())/(24*60*60*1000);

Where startdate and enddate are valid Date objects.

answered Jul 23 '12 at 16:38

Niet the Dark Absol

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if i'm collecting a date from a form field like this: var startdate = document.forms[0].datescopestart.value; The format returned is dd/mm/yyyy i.e 23/07/2012 How do I turn it into a vaild date oject? – labman Jul 23 '12 at 21:12

calculate days between dates

3 Answers3

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