Formatting CRM DateTime Field

As you might have noticed CRM DateTime field DataValue returns the following value: “Tue Sep 29 13:00:00 PDT 2009”
Sometimes you need to change the value to another format e.g. dd/mm/yyyy or mm-dd-yyyy hh:MM.
This is quite easy to do with C# since the format string is pretty extensive however the JavaScript Date object is pretty slim and so the only option is to write your own framework / prototype extension.

The following script extends the JavaScript Date Object and adds a toFormattedString function which accepts common format strings such as
dd – days, mm – months, yyyy – full year, hh – hours , MM – minutes , ss – seconds , ms – milliseconds , APM – AM/PM
You can extend the prototype function further if you require additional formatting.

Here is the code and usage example:

Date.prototype.toFormattedString = function(format)
{
   var d = this;
   var f = "";
   f = f + format.replace( /dd|mm|yyyy|MM|hh|ss|ms|APM|\s|\/|\-|,|\./ig , 
   function match()
   {
      switch(arguments[0])
      {
         case "dd": 
            var dd = d.getDate();
            return (dd < 10)? "0" + dd : dd;
         case "mm":
            var mm = d.getMonth() + 1;
            return (mm < 10)? "0" + mm : mm; 
         case "yyyy": return d.getFullYear();
         case "hh": 
            var hh = d.getHours();
            return (hh < 10)? "0" + hh : hh;
         case "MM": 
            var MM = d.getMinutes(); 
            return (MM < 10)? "0" + MM : MM;
         case "ss": 
            var ss = d.getSeconds(); 
            return (ss < 10)? "0" + ss : ss;
         case "ms": return d.getMilliseconds();
         case "APM": 
            var apm = d.getHours(); 
            return (apm < 12)? "AM" : "PM";
         default: return arguments[0];
      }
   });

   return f;
}

function OnCrmPageLoad()
{
    var d = new Date(crmForm.all..DataValue);
    alert(d.toFormattedString("mm-dd-yyyy hh:MM:ss ms"));
    alert(d.toFormattedString("dd/mm/yyyy hh:MM APM"));
}

OnCrmPageLoad();