Calendar size

When the form appears on my webpage, the calendar is a little distorted. One of the columns hangs over the side and the font is too big for the calendar.

I tried using bootstrap code I’ve seen in other threads and on the FAQ page, but only the standard seems to appear. (I don’t really know the difference though, so I can’t say much more than that.) What can I do to rectify this?

The form is currently on http://www.danieltaylorwrites.com/for-preneurs