Now a context manager is used to always close and commit.
Added .DS_Store to .gitignore.
Added a "Now" button for the date entry.
Deleted extraneous beginning line space.
Added a panel of (unimplemented) view buttons.
Replaced main with an application class.

This was done because there was starting to be a large
number of global variables, and I was started to forget to
mark them as "global" which could have resulted in
annoying bugs.