[Stephen Sanders]

I’m really reviving this thread (sorry!) but I had a similar problem (I hadn’t properly kept track of my time spent for a project), so I found a few options

https://activitywatch.net/ – this is free, open source, so I like it, and am using it right now

https://timingapp.com/ and https://manytricks.com/timesink/ seem useful, but I didn’t want to spend money.

Hope this helps someone!