A microspan was a small unit of time used on Gallifrey, (AUDIO: Weapon of Choice, et al.) shorter than a span (AUDIO: Forever) but longer than a nanospan. (AUDIO: The Inquiry) 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: Gallifrey[additional sources needed]) Although Time Lords on Gallifrey used the term liberally, the Doctor never attempted to make their companions learn about the unit.
A Timonic Fusion Device could be armed for detonation in 45 microspans. (AUDIO: Weapon of Choice) Lord President Romana had a feature in her Presidential TARDIS which allowed for materialisation to be paused for two microspans. (AUDIO: A Blind Eye)