Need support on a work tracker for my employees that will be a share document

Hello,

I am trying to create a simple productivity tracker for my team, I have a lead and clerk that would be doing the data entry on it, so i would lock all the important tabs. But realistically, i would like to have a button that starts a timer, (date/time assigned) in this column. And another timer to end it in the (date/time turned in) Column. I would need it to be for multiple employees at a time. i figure the button would be in the assigned/turned in columns.

For a mental image of how i see this going, Clerk/lead hands work to employee, hits button on timer to set the start time for this particular order in date/time assigned . Order is turned back in, clerk/lead hit button to indicate employee is finished and time is listed in turned in tab, time needed tab calculates how much time was needed.
I would like to have it in the table format so i can spit this data out into some pivot tables so i can track individual employees.

If there is a better way to do this, I'm all ears. If a formula or something works, I'm open to that too.

^{Table formatting by ExcelToReddit}

This is what i have so far