Its complicated!
There's a function to alter the clock by 1 hour for Daylight Saving (another name for British Summer Time)
(1) Get in and shut the door, turn the key to 'on' but don't start car. Wait for all the checks to finish. The mileage and time will show (You can't alter the clock with the engine running, or a door open, or without the key)
(2) Now, press top right button [Trip] by the display --SETUP appears on screen
(3) Press the [+] key to left of display until DAYL. SAVING appears
(4) Press bottom right button [Mode] by display until 'ON' shows.
(5) Press and hold top right button to go back to 'normal' display
(6) In October, do this all again to go back an hour
Think that's right. To set the clock itself, as above but at (3) needs to say TIME, then bottom right to select HOURS, use [+] and [-] to alter, press lower right to select MINUTES, again [+] and [-] to alter, then press and hold top right button to revert to normal.
I've had the car seven years and still have to look this up!
Pete