• Professor Urban Chronotis
• Played by Andrew Sachs

Professor Urban Chronotis, otherwise known as Reg, is the Regius Professor of Chronology and fellow of St. Cedd's College, Cambridge.

The position was created by George III, a monarch whose fear of the effects of time flowing backwards were heightened by his increasing insanity. The role of the post was to answer three fundamental questions about the nature of time. The answers are yes, no and maybe (in that order).

He was the pastoral tutor of Richard McDuff, although otherwise he has no apparent academic duties.

Donnish in manner and appearance has an increasingly bad memory and a childlike enjoyment of conjouring tricks. His age is described as "on the older side of completely indeterminate".