Time Keeping

For anyone who tries to keep a record of time spent on different tasks, what software (if any) do you use?

In an old workplace there was a bespoke "clocks" system where you could have 10 clocks open with pre-completed "tasks" assigned to each and a description of work completed - with a click of a button one clock would start and it would stop the previously running clock.

I am looking for something similar or better.... any tips?