This would require saving the entire year of logs and never clearing out the old logs. I am sure that drastically slow the system down. I don't think I am for that. I made a super simple spreadsheet that keeps track. I just put in the dates for when I left home and when I get back. The spreadsheet tells me how long I was gone for each run, total days out for the year and even a percentage of "time away from home. If you would like a copy, email me:
nathan at drivernotify dot com

A very helpful feature for US 70/8 is to recognize (34 hr) home address time for per diem days out. With a total at the end of the year.