When you configure the time zone in a contactable times set, you define the time that the campaign can contact a time zone during that time zone’s local time. For example, if your local time is Eastern time and you created a contactable time set to connect from 1pm to 2pm Central time, the campaign can start contacting at 2pm Eastern time (1pm Central time). 

To support the contactable times feature, the contact list must have a time zone column. For more information, see Contactable time sets overview.