Click the Date & Time icon, or open the View menu and click “Date & Time”. Note: If the padlock at the bottom of the window is closed, click it and enter an administrator name and password. Select the “Date & Time” tab, if it isn’t already selected.
Select “Set date & time automatically: to set your date and time according to one of Apple’s Network Time Protocol (NTP) servers”.
Select the “Time Zone” tab. Note: If the system is unable to determine your location automatically, uncheck “Set time zone automatically using current location” so you can manually set your location.
On the world map, select your time zone region.
From the “Closest City” drop-down list, choose Indianapolis for Eastern Time or Chicago for Central Time, etc.