Interstitial time

Interstitial time was the time between "now" and "now." The Master, under the alias of "Carl Thascales," researched and experimented with interstitial time using TOMTIT. Though his ultimate goal was to access the Crystal of Kronos to release Kronos, he was able to slow down time around the area and pull objects from other times. (TV: The Time Monster)

Jeremy Winterdawn, using Thascales' notes in 1994, continued exploring the concept of interstitial time through use of the metahedron. This actually allowed him and the Seventh Doctor to enter the interstitial gap, but aided in the creation of Gabriel and Tanith. (PROSE: Falls the Shadow)