Don't know how often the same birth dates crop up in your lives but my mother, my husband, my lifelong best friend and my aerobics teacher (for 20 years) all share the same birthday.
When my BIL was in military and stationed across the country, my SIL missed her mom terribly but could not afford to call her mom, so out of loneliness SIL bought herself a humane society dog and named her after my MIL. Missing her daughter, one day my MIL went out and bought herself a humane society dog and named her after her daughter. When SIL finally moved back to NH (bringing her dog) not only did they discover they bought the dogs on the same day, they noticed the two dogs were almost identical in appearance (same black and white markings) and looked like they could have come from the same litter.