Local time for mutt email display

I use mutt as my email client. Something that has recently been bugging me is that when reading a message it displays the original Date: header with the sender's timezone. Since I work with people in several different zones I am constantly having to do timezone math when looking at these. So I decided to fix that with a bit of python. One of mutt's features is that you can feed every email you view through a filter by using the display_filter setting.