Restored session timer

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?

As far as timing how long it takes, it does not look like there's any inbuilt function to handle this sort of thing(feature request maybe?). That said, the total bruteforce time and the time remaining will not be inconsistent so after restarting and eventually finding your plaintext(assuming you do find it before exhausting the keyspace) you can easily subtract the last given time remaining from the initial time remaining when you first started to see how long it took.

For example:

Lets say your attack will exhaust in 3 days total. You start and stop it a few times and then you find the password you are after. Right as you find the password, the status says you still have 1 day remaining to exhaust the keyspace. You can easily subtract 1 from 3 and find out that it took 2 total days of cracking, regardless of when those 2 days actually happened.