Date object not catching comparisons in google scripts (javascript)

Question

I have a script that is comparing two dates against each other. But both are coming in differently. one I converted to a string format Mo/day/year then to a date format. The other is taken directly for a google spreadsheet cell already in date format. But when I run a comparison on them, it doesn't work even if the date falls within the comparison range. Here's my code:

 function formatDate(someDate){
  var x = someDate.split("T");
  var v = x[0].split("-");
  var newDate = new Date();
  newDate.setFullYear(v[0],(v[1]-1),v[2]);
  //var newDate = v[1]+"/"+ v[2]+"/"+v[0];

  return newDate;
  }

 //calling formatDate within another function
 if(startDate != ''){
    if(singleCard[j].date != undefined){
      var k = singleCard[j].date;
      var f = formatDate(k);
      var dt = new Date(f);

 if(dt >= startDate && dt <= endDate){  //date comparison
   //do something here
 }

The start/end dates is coming in a format of:

    Fri Oct 12 2012 00:00:00 GMT-0700 (PDT)

The singleCard[j].date is coming in as a string:

    "2012-10-12T16:57:51.517Z"

and then I use:

   var f = formatDate(date) -> var dt = new Date(f)

to process it.
I'm not sure what I'm doing wrong here. Thanks.

Answer 1

When you do

var newDate = v[1]+"/"+ v[2]+"/"+v[0];

are you sure you used year / month / day in the right order ?

Did you try to log the result of var dt = new Date(f); to see its value as a date object ?

sorry if my questions seem obvious but since I don't know your local settings for date I can't be sure how you handle that.( I'm in a country where we use dd/mm/yyyy so I'm used to have problems with that ;)

EDIT : just saw your comment... shouldn't it be v[0]+"/"+ v[1]+"/"+v[2] (yyyy/mm/dd)

EDIT 2 : I think you have to give hh mm ss parameters as well when you use setFullYear();

something like

 newDate.setFullYear(v[0],(v[1]-1),v[2],0,0,0,0);

in order to get it working. It is also necessary (I'd even say mandatory) to set hh mm ss and mSec to 0 since you are using a <= and >= comparison, Equality will probably never be true if you let hours , minutes , seconds and milliseconds free to live their own life.

Don't forget date objects are ALWAYS complete dates with time, even when you don't show / use them.