I have two dates: ldBirthdate and ldPlanYear

ldBithdate = {07/01/1926}
ldPlanYear = {12/31/1997}

I need to know two things:

1) Did this person turn 70.5 (70 and 1/2) during ldPlanYear?
2) If not, which year did this person turn 70.5

For some reason all my calculations are not working. Perhaps I'm overtired? This should be pretty easy, right? Any help would be greatly appreciated.