Rel

A rel was a Dalek unit of measurement, principally of time.

The Daleks used rels for time measurement, (AUDIO: The Genocide Machine, The Mutant Phase, The Four Doctors, Blood of the Daleks, TV: Doomsday, COMIC: The Dalek Project) having inherited it from the Kaleds before them. (AUDIO: Guilt) A rel was approximately 1.2 seconds. (TV: Evolution of the Daleks)

In other contexts, it was a unit of speed. (COMIC: Plague of Death, The Emissaries of Jevo) A rel was also used as a unit of hydroelectric energy, not to be confused with a vep, the unit used for artificial sunlight. (The Dalek Book) When the New Dalek Empire tried to destroy the multiverse with a reality bomb powered by an arrangement of planets in the Medusa Cascade, they launched a countdown from two hundred rels until they would attempt to use it. (TV: Journey's End)

"Rel" was also used in an idiomatic sense. When Rose Tyler revealed she had been on a Lect ship, Glom said, "Wait a rel," before declaring she was with the "Riders". (COMIC: Weapons of Past Destruction)

When one Dalek predicted conquest of Earth in 9376 rels, the Thirteenth Doctor had trouble remembering how long a rel was. (TV: Resolution)

Behind the scenes
Before appearing in early Doctor Who comics, the word rel originated from the film Daleks' Invasion Earth 2150 A.D. starring Peter Cushing as Dr. Who. However, this wiki does not consider the Peter Cushing movies as part of the DWU.

Given that rels are established to be 1.2 seconds in TV: Evolution of the Daleks, the 9376 rels mentioned in TV: Resolution are approximately equivalent to 3 hours, 7 minutes and 31 seconds.