A boy is bar mitzvah'd automatically on his thirteenth birthday, no ritual required. Still, it's customary to have the young man called to the torah. It can be done on any day of the week that the torah is read - Monday, Thursday, or Shabbat (Saturday).
Grandpa holding the torah:
Bar Mitzvah lad at the torah:
Dad lifting the torah at the end of the ceremony:
Grandpa holding the torah:
Rabbi instructing on wearing tefillin:
Bar Mitzvah lad at the torah:
Dad lifting the torah at the end of the ceremony: