The race starts at 10am, so it's probably best to try to run as close to then as possible, with a similar breakfast to what you will have on the day. An hour either way won't make much difference though.
If you are planning a 10 miler this weekend, then you are in good enough shape to get round already. Relax and enjoy this weekend's run.
If you are going to be in Glasgow the night before, some of us are meeting up for pasta - details on the "Events" forum. And there are plans to meet up pre-race with some more forumites.