Time slippage

Time slippage was a form of temporal distortion.

The Laan caused time slippage when they travelled through the Time Vortex. (AUDIO: The Sands of Life) K9 was damaged by it, and the Fourth Doctor took a month to repair him. (AUDIO: The Justice of Jalxar, Phantoms of the Deep)

When the TARDIS encountered time slippage, it gave the Eleventh Doctor a premonition of terrible disaster. He tracked the source to the Darkstar Academy. (AUDIO: Darkstar Academy)