Restored session timer

Hey,

Is there any way of identifying the total cumulative time of a cracking session? I'm testing something where I want to find out how long a raw brute force takes to crack, but need to do it over several periods. Restoring my session each time though of course resets my 'Time Started' read out. My test should take about 3 days to crack but I don't really want to leave my system running the whole time.

Before I set up for a marathon cracking session is there any in-built functionality that can allow me to achieve this?

Thanks.