A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Let's say initial dates are in B2:B50 and revised dates in D2:D50.
Select D2:D50. I will assume that D2 is the active cell within the selection.
On the Home tab of the ribbon, click Conditional Formatting > New Rule...
Select 'Format only cells that contain'.
Leave the first dropdown set to 'Cell Value'.
Select 'greater than' from the second dropdown.
Enter =B2 in the box next to it.
Click Format...
Specify the desired formatting.
Click OK twice.