GMT
GMT was the time zone of the United Kingdom.
When it was 5 A.M. in the UK, it was simultaneously 6 A.M. in France, 8 A.M. in Moscow and 1 P.M. in China. This was noted on UNIT's digital world map listing deaths caused by ATMOS cars. (TV: The Sontaran Stratagem)
On 8:40AM GMT on a Wednesday in September 2009, numerous RTAs occurred across Earth as a result of the 456 compelling every human child to suddenly stop and proclaim their message: "we are coming." As noted by Torchwood Three, seventeen RTAs all involving children occurred between 8:40 and 8:41 across Britain from Glasgow to St Ives, fifteen occurred in France at 9:40AM French time, along with others in Norway, Sweden, Denmark, Luxembourg, Spain, Portugal, Bosnia, and Tokyo. (TV: Children of Earth: Day One)