Totally Random Search for Free Time-Tracking software
I personally have not reviewed any of these except a casual look. So be careful but not fearful.
Try Sourceforge first as it is an open-source site for freeware
[Sourceforge is a Developer’s Site for Free Software]
https://new.toggl.com/#signup – looks simple
https://www.teamfocus.me/go/time-tracking/ – more complex
Time Tracking, Billing Invoicing
Top 10 Free Time Tracking