
Calculating years of service in Excel is best done using the DATEDIF function, which accurately measures the difference between dates. For full years, use =DATEDIF(start_date, end_date, "Y"). For a breakdown that includes months, use =DATEDIF(start_date, end_date, "Y") & " years, " & DATEDIF(start_date, end_date, "YM") & " months," giving a detailed and precise result.


