.. When I'm odd...

First, this part of the riddle deals with the clock in room II.

You can set the time on the clock. So, we are looking for a number between 1 to 12, here.

Okay, it's a word play. An odd number becomes even, when one letter is removed.

Any number comes to mind when you add a letter to word even.

Seven! Seven minus one letter (S) is the word even.

Set the clock to seven.

You have to fix the pendulum for the clock to work.