Excel - IF Functions

Hi ,

I made a forumlua that finds the difference between the date of one cell against todays date to get the total number of days that have gone past since they started. I need help making a if function that will flag YES if the total of days in the cell = either 1 or mutipules of three thereafter ie 1,4 ,7 ,10 ,13

Any help would be appericated

Thanks