Time Quest Hint?

[Quack]

You're probably gonna laugh at me in the face, but can you please give me a hint on where to find the third number in the house, needed to open the basement door?

I got the 22 from the markings in the statues on the fireplace and the 163 from the housenumber, but I can't seem to find a third number... Please help me out with a subtile hint.

[Robert Eric]

The third number is in the bathroom, and it has to do with the window.

[Quack]

Oh, I see. I just thought there were some wrinkles in the curtains  
Thanks a lot!