birthday coincidence

My son, Jacob, had a sister born on his birthday, 27th September, he married a lady whose sister was born on the same date, one year later, 16th January, and they subsequently had two sons with the same birthday, 7th September. I would love to know what are the chances of this happening!
Total votes: 470
Date submitted:Sat, 14 Jan 2012 08:50:05 +0000Coincidence ID:3564