[Evolution] Evolution To-Do's

[David Ron <david BandMerch com>]

Does evolution keep all of my complete tasks indefinitely, or do they
expire and self-delete?  

I was hoping to us the tasks feature as a kind of diary at work to
remind myself what projects I had accomplished and when.  But, if they
are removed after a certain time, this would not be a good idea.

Thanks.
-David