Facebirthing
A person who thinks your birthday is wrong because Facebook said so, even if you told them it was wrong.
'My birthday is April 5th, but Facebook said it was March 2nd, so now I think I was born in March.'
'I told my friend my birthday was January 1st, but Facebook said it was December 31st, so now I'm confused.'
'My birthday is June 10th, but Facebook said it was June 11th, so now I think I was born on the wrong day.'