Track Active Employees by Day

I would set up a new table called employee daily record total. This would be a helper table that would just have one record in it. So you create that one record and then lock down anybody else for Adding records. 

The record ID will be record ID number one. Then you would create a relationship back to your employees table using a formula reference field of a formula numeric equal to a formula of 1.

Then you would make a summary field of the number of active employees.  We will also need to have a helper field called [Today] with a formula of Today().

OK so that gives you the active employee count for today, but how do you create the history?

What I would then do is have a new table called employee count history. It will have two tables. The date and the total number of employees. 

Then create an automation to run either seven days a week or five days a week which would copy the value of that summary table and copy the value of today into the date field and obviously the total number of active employees into the employee account table.