Locating the calendar file?

I’ve search everywhere for this, but I can’t find it yet, I’m wondering if anyone here could help me out.

I know that the code in this link will call my calendar;

http://codex.wordpress.org/Template_Tags/get_calendar

But there are no references made to where the actual file is, that’s so frustrating because there is no calendar.php file or a wp-calendar file.

I’m irked. Should be simple right? I looked at various other files, I still can’t find the calendar table, WHERE is wordpress calling the calendar from?

I have WordPress 2.03