Hi benfo,
In order to change the time zone that is reflected on the scheduler page within your Auctiva account, you will first want to mouse over the "My Account" tab within your account and select the "Acct Preferences" option under "Settings". You will then want to select the desired time zone from the "Preferred Time Zone" drop down menu and click the "Update Account Preferences" button below.
I hope this helps. If you have any other questions regarding your account, please feel free to contact our customer support team using the form on the following page of our site:
http://www.auctiva.com/help/requesthelp.aspx-Mike