How does the eBay API return time stamp data?
Time values in the API may appear to be different from the time stamps on the eBay.com and the Sandbox. The API returns time-stamps for events and transactions in Greenwich Mean Time (GMT). The eBay.com Web site displays time values in a local time zone. Unless otherwise specified for a particular tag or function, all Time values in the API are in GMT.
If you prefer to display or work with Time values in a particular time zone, your application needs to handle the conversion between GMT and that time zone. Searching for 'time zone' on the Internet will unearth a number of relevant links for determining time-zone conversions.
http://developer.ebay.com/devzone/guides/ebayfeatures/Basics/DataTypes.html#TimeValues provides an in-depth discussion of time-zone specifics in the eBay API.