The UI could be improved in a few spots, but they aren’t major issues:
It may be necessary to adjust the text wrapping or to remove it completely.
The buttons should be titled “Start time” and “End time” without an underscore.
Also, I noticed that the week begins on Sunday. In Finland (and many other countries), the week starts on Monday.
Despite what might appear, the room is not already selected. It looks a little weird.