Determines the number of years and fraction of a year between two dates.

YEARFRAC(StartDate, EndDate, Basis)

StartDate: date from which the difference is to be measured.

EndDate: date to which the difference is to be measured.

Basis: parameter which describes how to calculate the difference based upon the following:

• 0: years + months/12 + days/365
• 1: years + months/12 + days/360
• 2: years + months/12 + days/365.25
• 3: match Excel default (US NASD 30/360)

YEARFRAC(DATE(1,1,2017), DATE(10,1,2017), 0) will return the value 0.75