Thanks very much Etienne. The timings information is helpful. Just want to be able to say to my son, "They will let you know when you have five mins left", or if they get a one minute warning and he hasn't finished I just want to let him know what to do. I don't want him to go in expecting a 1/5 min warning and then there isn't one and he thinks he has more time than he actual does have!

Last year my DC told me that there were instructions on the CD but (unlike previous CEM tests) there were no start and finish times written up on a board. Therefore he made a note of the start and finish times on the question paper at the start so that he could check his watch and know where he was instead of waiting for a 5 and 1 minute warning.

Why not just tell him to listen VERY carefully to any instructions given? If he goes in expecting one thing - that you have told him - and CEM change it (which they are notorious for doing) then that will throw him - if he knows he is responsible for listening to the instructions then he won't be thrown.