How to change default date language?

[shawn_a]

nothing, that is the function as it exists in 3.3.x

you can change the argument to whatever you want say
get_page_date("F jS, Y - g:i A") for example

now if you know php , you can look at this function in the master branch on github and see how it uses the new formatDate() function that was created to use strftime instead of date()

or give us the format you want and maybe someone will write a function for you.