I found previous references to this problem, but they were quite old and seemed to indicate the problem is fixed, which it isn't for me.
I am using an iPhone 4 with iOS 5.0.1.
My app version is 4.5.8.
My phone has the time zone set automatically to Sydney, Australia, which is correct.
I have my time zone in my geocaching account set set to Sydney, Australia.
The problem occurs every time I post a log from my phone. Today, the 14th of Dec 2011, I logged finds for 7 caches between 1pm and 4:30pm. When I look on the website all of these logs are set to 13/12/2011. If I look at one of the caches that I found today in the iPhone app, it shows the download date as today and the last found date as tomorrow.
I would expect that the date would be correct as per my phone's date.
My current date and time is 14/12/2011 17:22.
Thanks
John