I'm trying to have multiple cells display the time when text is entered into
the adjacent cell.
So I have this

=IF(ISBLANK(B6),"Please Log In",NOW())

I have two people accessing the file putting a check in the box when they
arrive, then it displays the time they logged it. But because the NOW()
function recalcs each time I lose the data.

How do I freeze the NOW() function so we can keep track of the data without
having to copy and paste as values each time?