CLOCKS 'SPRING' FORWARD...

In SPRING the clocks 'spring forward' (and in AUTUMN they 'Fall' back) so today 1am becomes 2am. 

In the UK the clocks go forward 1 hour at 1am on the last Sunday in March, and back 1 hour at 2am on the last Sunday in October.  (This is our educational slot, by the way!)

Although GMT (Greenwich Mean Time) and UTC (Coordinated Universal Time) share the same current time in practice, there is a basic difference between the two:

GMT is a time zone officially used in some European and African countries. The time can be displayed using both the 24-hour format (0 - 24) or the 12-hour format (1 - 12 am/pm).

UTC is not a time zone, but a time standard that is the basis for civil time and time zones worldwide. This means that no country or territory officially uses UTC as a local time.

UTC, GMT and Daylight Saving Time...

Neither UTC nor GMT ever change for Daylight Saving Time (DST). However, some of the countries that use GMT switch to different time zones during their DST period.

For example, the United Kingdom has British Summer Time (BST), which is one hour ahead of GMT, during the summer months.