Preventive Schedule Automatic Plan Visit

Are you looking for a VBA macro to do the highlight or a formula if, at all, possible?

How about conditional formatting to highlight your cells?
As your table is a monthly one, I added a Month column where you enter the number of month between maintenance.
If a maintenance is done multiple time per month, you enter 1. Bimonthly =2. Quaterly=4 etc.
This is because any maintenance done more then once in a month will be shown highlited every month.
See attached workbook for a working conditional formatting for rows 2:8
I hope this will help you.
here is ine of the conditional formula. It will return 0 when it is time for the maintenance:

=MOD(MONTH(Q$1)-MONTH($N$7),$M2)=0

And here is the other conditional formula. It looks at the end date and revert the previous conditional formating.

=Q$1>$O2

Thinking about this, you might need one to look at the beginning date and make sure the maintenance is not
highlighted if the column month is before that date.