24hr clock iCal

If I need to enter an event into iCal at a time before 08:00 using 'create quick event'. Let's say '03:30 Heathrow' it shows as Heathrow 15:30 in iCal. This only happens for events between 01:00 and 07:59. Not a lot of good to turn up 12hours late
If I add the time as 03:30am it will work. Do some people not work between 01:00 and 08:00?
Using Lion 10.7.3 iCal 5.0.2
Any advice?
TIA
Ian

iCal relies on the setting you have set up for "date and time" in system preferences. So adjust it there.

May thanks for the reply. I have set that up under the direction of the guys at applecare. When they tried it, they too had the same problem. I have tried two other calendar programs with the same problem. I also have the problem with Google calendar that too suffers in the same way. Could be the OS? Time will tell.
Ian