This isn’t exactly what you’re looking for, but when I was at REI, there were different hourly rates based on the job I was performing…then there were pay changes like raises where I didn’t want a change to be retroactive and change all my past data.
Here’s a doc I created then that is a little more complex, but a similar schema could be used for each person to have an hourly rate and even track if they change that rate on a particular date.