incorrect start date for anonymous users

Hi,

On a meeting scheduler I created that allows anonymous users to enter their name and date/preference, they see the start date as beginning a day earlier than I set. e.g. If I set Dec 16, 17, 18, 19 as the start date, users who are not logged in see Dec 15, 16, 17, 18.
It works as expected for users who are logged in.

Please help. Thanks.

Kamal