My discovery on DATEDIF ("yd") and leap year

A1:A4

2/1/2007
3/1/2008
2/1/2008
3/1/2009


formula (1) =DATEDIF(A1,A2,"yd") yields 28

formula (2) =DATEDIF(A3,A4,"yd") yields 29

I understand why this is happening - the year for the first argument is used.

I find DATEDIF and "yd" and leap year "interesting," "temperamental," "confusing," ...... <g

I am curious if "yd" is used often.

Welcome comments to this and my discovery.

Epinn