Rest week and half marathon time

This is my rest week coming up, so naturally I'm signed up for a local half marathon.  I've never raced this distance before (my PR on the left side came from my last full marathon).  Since it's a rest week, I think I'll take off an extra day and probably run the half marathon at no more than 90%.  Most likely I'll use it to simulate the first 13.1 miles of a real marathon.