Small library staff/volunteer schedule application

So over the holiday weekend I decided to set up a small application to manage the schedule at my (previous) library. I had been thinking about it and tinkering with it for a while but I finally got it into production.

Feel free to have a look about at a mirror of it at the username is admin and the password is 1234.

I'm taking this install down eventually so feel free to muck about and create users and modify things.

I'd appreciate and criticism or suggestions.