Calendar Countdown was the first British adaptation of the Des chiffres et des lettres format, and the forerunner of Countdown itself.

The series was broadcast only in the Yorkshire TV region, on Monday evenings at 6:30pm (immediately following the region's news programme, Calendar) for eight weeks, from 19 April to 7 June 1982. The host was Richard Whiteley, the letters hostess was Cathy Hytner, and the Vital Statistician was Denise McFarland-Cruickshanks.