Volatile Time calculations

[JumboCactuar]

Hi,
I'm wanting to calculate a time from when a user clocks in to the current time though unsure the best way to go about it.

Currently I have a cell with now()
Then subtract the clock in time from current time.

Though this makes all the cells volatile right? Is there a better way to do this for 300 people?

 

[ranman256]

That's how I do it. But not use the formula, it places the value.(form)

A 3rd column is difference in minutes,
then I add the minutes/person to calc hrs.