Belize is on Central STANDARD Time.
Some of the regions of Canada and the USA that were on CST are now on Central DAYLIGHT Time.
CDT = CST + 1h
Similarly, some of the regions that were on Eastern STANDARD Time are now on Eastern DAYLIGHT Time, and some of the regions that were on Mountain STANDARD Time are now on Mountain DAYLIGHT Time.
Belize doesn't utilize daylight saving time, so we didn't change our clocks, therefore we're still on CST.
On 27 March, Britain will begin daylight saving time and will be known as British Summer Time (BST). GMT does not change, so Britain will be GMT+1h or UTC+1h.