A supervisor at a London telephone exchange, in 1963 Simmons won a £500 competition to replace Jane Cain, whose voice had been used since the service began in 1936.
On 2 April 1985, Pat Simmons' last words on the clock were: "At the third stroke it will be 10:59 and 50 seconds", followed by the three pips and then the voice of Brian Cobby who succeeded her in the job.
In 2000, a project called TIM 2000 was run by the Telecommunications Heritage Group to recreate the Pat Simmons speaking clock.
[1] The Speaking Clock machine that was used by Pat Simmons was displayed on an edition of the BBC television programme, Antiques Roadshow, originally broadcast on 19 October 2008.
About forty-four minutes into the programme, Alan Midleton, who had made past appearances as a watch and clock expert on the show in previous episodes but was appearing as a curator of the museum, claimed that the electric motor of the machine, which had been running at the institute, broke down on the same day that Pat Simmons died.