changing SharePoint calendar from SUnday Monday.....Saturday to Sun, Mon,...., Sat

[null null]

I am trying  to display the calendar with headers as Sun, Mon, Tue rather than Sunday, Monday, Tuesday.However, whenever next and prev is clicked, it comes back to default. 

So i have applied the script in the console to check ; its for nextbutton(first line below)

document.getElementById('WPQ2_nav_next_a').click(); 
$("th.ms-acal-month-top span").text(function(i, t) {    return t.substr(0, 3)   });

It changes for a millisec but then i think Ajax takes over.

Is there a way i can have the second line executed at the end.

[#2]

Wait for the body to be loaded, then check for the element to be ready and do you change. If the element is not ready yet, set a timer, and redo the check.

[#3]

is there a sample code for that.