Each user can have her own time zone settings. Where applicable, this time zone settings is used instead of the web site's default time zone. User's time zone can be set in both CMS Desk and Site Manager, on the Administration -> Users -> Edit user -> Settings tab. On the tab, the selection can be done using the Time zone drop-down list.
Page url: http://devnet.kentico.com/docs/devguide/index.html?setting_users_time_zone.htm