parseDate

parseDate.js

function parseDate(str, format) {
  format = format || 'yyyy-mm-dd'; // default format
  // build a regular expression to match the format
  var i = 0, fmt = {}, 
      re = new RegExp('^'+format.replace(/(yyyy|dd|mm)/g, function (match) {
        fmt[match] = ++i; // store format position
        return '(\\d{'+match.length+'})'; // make a capturing group
      })+'$'), parts = str.match(re); // match the date parts

  if (!parts) return null; // input didn't match the format pattern
  
  return new Date(parts[fmt['yyyy']], parts[fmt['mm']]-1, parts[fmt['dd']] || 1);
}

console.log(parseDate('06-01-2010', 'mm-dd-yyyy'));
console.log(parseDate('01.06.2010', 'dd.mm.yyyy'));
console.log(parseDate('06-01-2010', 'mm-dd-yyyy'));
console.log(parseDate('01-06-2010', 'dd-mm-yyyy'));
​console.log(parseDate('01/06/2010', 'dd/mm/yyyy'));
console.log(parseDate('06/01/2010', 'mm/dd/yyyy'));
console.log(parseDate('2010-06', 'yyyy-mm'));
console.log(parseDate('2010-06-01'));​