Isso foi perguntado no site da Microsoft e foi dada uma resposta que pode ajudá-lo. Clique aqui para ver: link .
A resposta que eles deram é a seguinte:
I have searched for this feature extensively and couldn't come up with anything. It simply doesn't exist and for some reason Microsoft won't do anything about it. I don't understand how it could be that difficult.
Anyway, I've come up with a solution that works for me, because I don't really like having to look around the month view for where today's date is. I just created a new appointment named "Done" (for days that are past) and categorized it in a new category called "Done Days" which I put a black label on. Of course, you can use red, pink, green, or anything else that suits your fancy, but black shows up well for me. I then posted that appointment on a day in the past and set it for "All Day" so that it wouldn't remind me. If you click on the appointment once, just so that it selects it, you can hit Ctrl+C to copy and then click on any other day, and hit Ctrl+V to paste it into any past days.
This way, any past days have a black bar through them that says "Done" and at the end of a day, all you have to do is select one of those bars, and copy and paste it to the current day. Maybe it's just me, but I think it's kind of satisfying to check off a day this way.