A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Let's say you have a start date in cell D2.
Enter the following formula in another cell, for example E2:
=DATEDIF(D2,TODAY(),"Y")
This can be filled down if applicable.
Select D2 (or the entire range you want to be highlighted conditionally)
On the Home tab of the ribbon, click Conditional Formatting > New Rule...
Select 'Use a formula to determine which cells to format'.
Enter the formula
=MONTH($D2)=MONTH(TODAY())
Click Format...
Activate the Fill tab.
Select a highlight color.
Click OK, then click OK again.