Microspan

A microspan was a small unit of time used on Gallifrey. As employed by Lord President Romana, Darkel and K9 Marks I and II, it seemed to indicate a length of time somewhere between Earth seconds and minutes. (AUDIO: all of Gallifrey) Although Time Lords on Gallifrey used the term liberally, the Doctor never attempted to make his companions learn about the unit.

The materialisation of Romana's presidential TARDIS was once paused for two microspans. This lasted a little under one minute. (AUDIO: A Blind Eye)

A unit of the same name was also used by Terpsivores. Twelve Terpsivorian microspans were less than two minutes. (COMIC: Death Disco)