JSON date fromat to date Object

<pre class="brush: c#">
//JSON date fromat to date Object
var jsondtobj = function (txt) {
var year, month, day;
var filler = '.*?'; // Non-greedy match on filler
var yre2 = '((?:(?:[1]{1}\\d{1}\\d{1}\\d{1})|(?:[2]{1}\\d{3})))(?![\\d])';
// Year 1
var yp = new RegExp(filler + yre2, ["i"]);
var ym = yp.exec(txt);
if (ym != null) {
var year1 = ym[1];
year = year1.replace(/</, "&lt;");
}


var mre2 = '(?:(?:[0-2]?\\d{1})|(?:[3][01]{1}))(?![\\d])'; //
Uninteresting: day
var mre4 = '((?:(?:[0-2]?\\d{1})|(?:[3][01]{1})))(?![\\d])'; // Month 1

var mp = new RegExp(filler + mre2 + filler + mre4, ["i"]);
var mm = mp.exec(txt);
if (mm != null) {
var mon1 = mm[1];
month = mon1.replace(/</, "&lt;") - 1;
}


var dre2 = '(?:(?:[0-2]?\\d{1})|(?:[3][01]{1}))(?![\\d])'; //
Uninteresting: day
var dre4 = '(?:(?:[0-2]?\\d{1})|(?:[3][01]{1}))(?![\\d])'; //
Uninteresting: day
var dre6 = '((?:(?:[0-2]?\\d{1})|(?:[3][01]{1})))(?![\\d])'; // Day 1

var dp = new RegExp(filler + dre2 + filler + dre4 + filler + dre6, ["i"]);
var dm = dp.exec(txt);
if (dm != null) {
var day1 = dm[1];
day = day1.replace(/</, "&lt;");
}
var dateObject = new Date(); dateObject.setDate(day);
dateObject.setMonth(month); dateObject.setYear(year);
return dateObject;
}; //
</pre>