Here is my offering (assumes "hire date" is in A1)...

=DATEDIF(TODAY(),DATE(YEAR(TODAY())+(DATE(YEAR(TOD AY()),MONTH(A1),DAY(A1))<TODAY()),MONTH(A1),DAY(A1 )),"d")

Which, in comparing it to Sandy's, is the same except that mine eliminates
the call to the MAX function that Sandy used.

Rick