Hypertime is a fictional concept in DC Comics. It is a variation of the Multiverse concept that existed in DC Comics before Crisis on Infinite Earths.
The concept of Hypertime first appeared in the 1999 The Kingdom limited series. Hypertime is a network of alternate timelines that branch of from the DC Universe. These timelines sometime overlap with the DC Universe and with each other on occasion, allowing for alterations in reality. Characters from one timeline can cross into another timeline if needed.
The Hypertime concept was used on and off in various DC titles from 1999 to 2005, although some writers found that their attempts to use it were either outright rejected or their stories severely altered to allow no attempt to further expand upon the concept.
In July 2005, DC Executive Editor Dan DiDio renounced the concept of Hypertime, stating it would no longer be used in future DC titles.
The 2005-2006 Infinite Crisis limited series replaced the concept of Hypertime with reality-altering shockwaves created by Superboy-Prime when he punches the walls of his extra-dimensional home. Dan Didio said in a interview in January 2006 that "The great part about Crisis is that all mistakes and retcons are time anomalies."
Mister Mind, disguised as Skeets, confronts Waverider and refers to him as "the seer of Hypertime" and divergent timelines. Dan Didio stated in an interview in September 2007 that "each Earth has its own parallel dimensions, divergent timelines, microverses, etc".
A future version of Booster Gold mentions the concept of Hypertime to his son Rip Hunter. The older Booster Gold explains that he personally erases divergent timelines from various alternate Earths in order to set the timeline of each Earth to a fixed, cohesive state.
Hypertime is used to explain the formation of, and changes to, the 52 universes formed at the end of 52.