Question

What is best way to convert date from JavaScript string in format YYYYMMDD to JavaScript date format.

var from_date = document.getElementById('from_date').value;             
var YYYY = from_date.substring(0,4);
var MM = from_date.substring(4,7);
var DD = from_date.substring(7,8);      

Answer 1

var myDate = new Date( parseInt(YYYY,10), parseInt(MM,10)-1, parseInt(DD,10) );

note that the month provided to the date constructor is actual month number – 1.

edits: ok, there are some issues with your date part extraction- substring is probably the most awkward of javascript’s sub-stringing methods (sub,substr,substring). And after testing I stand by the month value having to be 1 less than the actual number. Here is a fixed sample.

var from_date = "20101127"; //document.getElementById('from_date').value; 
var YYYY = from_date.substring(0, 4);
var MM = from_date.substring(4, 6);
var DD = from_date.substring(6);
var myDate = new Date(parseInt(YYYY, 10), parseInt(MM, 10) - 1, parseInt(DD, 10)); 
alert(myDate); // should be november 27th 2010