Private Sub BirthDay_AfterUpdate()
intYearsOld =datediff("yyyy","#" & me.[BirthDay] & "#",date)
if datepart("m",#" & me.[BirthDay] & "#") < datepart("m",date)= False then
intYearsOld = intYearsOld - 1 'Just In case they have not had their birthday yet this year.
end if
me.[Age] = intYearsOld
end sub
This is accurate up to the month. If you want to go further add to the If statement and ElseIf datepart("m",#" & me.[BirthDay] & "#") = datepart("m",date)
if datepart("d",#" & me.[BirthDay] & "#") < datepart("d",date) then
intYearsOld = intYearsOld - 1
end if