Anti-time is a chronometric plane inverse to regular time.
The Devron System IncidentEdit
An eruption of anti-time caused by the explosion of the USS Pasteur's warp core and a weakened time-space continuum due to an inverse tachyon pulse from the Pasteur in 2395 and USS Enterprise-D 2364 and 2370 occurred in the Devron system . The eruption enlarges as one moves back in time. This means that in the distant past the eruption actually disrupts the origin of life on Earth.
It should be noted that the Devron system is about 33 light-years from Earth and that the anomaly would have destroyed life in a sphere 66 light-years in diameter. However this is called into question by Q’s words that the anomaly is the size of the quadrant which means 4 billion years ago the Devron system was half a quadrant away from Earth. (This is possible due to stellar drift).