Beyonce & Jay Z's twins: Rumi & Sir Carter's birth details revealed

Rumi Carter will always have bragging rights over her little brother.

That's right—Beyoncé's newborn daughter was first to be born, E! News has learned. However, while Rumi arrived at 5:13 a.m., Sir Carter also made it into the world before the clock struck another minute. 

As for their mysterious birth date, it's confirmed that they were born on June 13, 2017. Unlike their famous parents and big sister Blue Ivy Carter, who all have middle names, the newest members of the Carter family only have first and last names, so those "Sir Carter Carter" rumors can be put to rest.