Schaz, I think that having them on different days would be confusing for them I personally would never consider it but hey, its up to you. Jack and Charlee are as individual as you can get. But knowing that they share a birthday is so so special. They play and chatter in baby language to each other. They are boy/ girl so not identical but as individual as they are they are twins and that is something I wouldn't want to take from them IYKWIM???? Its pretty special being twins, growning up best friends. I think a shared birthday would be the icing on the cake! Pardon the pun!