Almost the same birthdays

Ammar and I compared how much Nadia was so alert when she was born compares to Aidan. He sleeps the whole day, we hardly seeing his eyes opened.
Sari thought maybe because he was born 7 days earlier than the due date, and Nadia was born 3 days after the due date, so he is about 10 days apart.... which is a lot for newborn.

Then the thought came to Sari's mind.. she started counting.. hey.. if he was born 3 days after his due date, his birthday would be only 2 days apart, he would be on the 2nd of March, and Nadia is on the 4th.
How that happens ? We will have trouble celebrating birthdays every year then.

Now, his birthday is only 12 days apart from hers.