Well LK made it real simple...I think.
Kerry born on Feb. 28 at around 11ish pm.
Terry born on Mar. 1 at around 1ish am.
During leap year, Kerry celebrated her birthday and her twin bro Terry celebrated his two days later on Mar. 1.
If this is correct, then I say remove this post and keep the puzzle open. If this post remains, it will be yet another way of explaining it, but not necessarily the correct way.