Hi all.
I have an iphone 16gb 3gs with ios 4.0.
Have been noticing that when i enter any appointments in the iphone calendar, it will put it a day later eg. enter an appointment for 3pm on the 16th, when viewed in cal it puts it at 3pm on the 17th??  Any ideas on how to fix? 
I'm figuring that i'll have to update to newest ios, but will this fix the problem?

Thanks in advance.