A time fissure was a weakness in the fabric of time and space.
Sarah Jane Smith sends "Oscar" home through the Time Fissure (SJA: The Temptation of Sarah Jane Smith)
Common effects
Places that were reputed to be haunted usually had a time fissure nearby. They were also often responsible for disappearances, as people accidentally wandered through them and got lost in time. Growing up near a time fissure tended to enable one to develop psychic powers such as precognition and "second sight". (DW: Image of the Fendahl)
History
The English village of Fetchborough was situated in or near a time fissure. Consequently and because of her long exposure to the fissure, a local, Martha Tyler had a reputation as a witch. The presence of the fissure made Fendelman's 1970s experiments with "Eustace", the skull of a Fendahl Core, even more dangerous. (DW: Image of the Fendahl)
Sarah Jane Smith, Mike Yates and K9 Mark III visited a house built over a time fissure. (ST: Housewarming)
In 2008, Sarah Jane and her team examined a time fissure seven miles from the former site of Foxgrove, a village which no longer existed. She used a device to open and close the fissure. When activated, the fissure manifested as a glowing portal through which people could pass. It seemed that the Trickster had created this fissure deliberately as part of a trap set for Sarah. (SJA: The Temptation of Sarah Jane Smith)