Birthday

A birthday was the anniversary of someone's birth.

River Song was taken by the Doctor for her birthday to the last Winter Frost fair on the River Thames in 1814. Stevie Wonder unknowingly performed before being taken back to his original time. River later implied to Rory Williams that on a birthday before this, two Doctors were present at the same time. (DW: A Good Man Goes to War)

When Sky was rapidly grown, Clyde Langer noted her lack of birthdays, remarking it was "rubbish". (SJA: Sky)