Timestamped 

A period of time when the truth is told by a friend

Mike told Kenny his girlfriend is a bitch at about 12 o'clock midnight.

Wow, he Timestamped his ass!

Timestamped by The Professional Timestamper March 6, 2009

TimeStamp 

The current date visible in a photo, e.g. written on a peice of paper or personin photo's skin, in order to prove the photo is genuine. Often used on /b/ when people post pics of themselves.

OP: Hey look at my huge titties

Anonymous: Timestamp!!!

TimeStamp by Dudey McCool October 17, 2009