Changing AJAXtoolkit:CalendarExtender day format

AJAX toolkit has a set of awesome controls, and very customizable too. But one property that is not customizable OOB is how the day names are displayed in the Calendar extender.
The displayed format is two letters only. But what if you want it to be displayed in three letters?
Here a small cosmetic surgery (i.e. code changes).

Before	After

So, what does it take to do it successfully?
I opened CalendarBehavior.debug.js, which contains the debug version of the extender's JavaScript. Day names were obtained from an array named: dtf.ShortestDayNames:

dayCell.appendChild(document.createTextNode(dtf.ShortestDayNames[(i + firstDayOfWeek) % 7]));

Searching the library code, I found that this array is defined in MicrosoftAjax.debug.js. as:

ShortestDayNames":["Su","Mo","Tu","We","Th","Fr","Sa"]

And fortunately, another array was defined with three letters names:

AbbreviatedDayNames":["Sun","Mon","Tue","Wed","Thu","Fri","Sat"]

So all what it takes is to replace ShortestDayNames with AbbreviatedDayNames in both CalendarBehavior.debug.js and CalendarBehavior.js:

dayCell.appendChild(document.createTextNode(dtf.AbbreviatedDayNames[(i + firstDayOfWeek) % 7]));

And build.

It's great to have the source between your hands :)