- Click on the Apple Menu in the upper left-hand corner of your screen and select "System Preferences."
- Click on the "Date and Time" icon in the Preferences Panel to activate the "Date and Time" preferences.
- Using Network Date and Time
Click on the "Date and Time" button at the top-center of the panel. The date and time can be automatically adjusted from a network time server, if your Mac is connected to the Internet, by checking "Set Date & Time Automatically." Your computer will adjust its internal clock to a central network server.
- Manual Adjustment of Date and Time
Set the date and time manually. If you are not connected to the Internet, de-select the "Set Date & Time Automatically" check-box and adjust the date and time using the date and time adjustment arrows above the calendar and clock. The date can also be selected by clicking on the corresponding calendar day. The time can also be adjusted by clicking on the time displayed above the clock and entering the correct time using the numbers on your keyboard.
Select your current and correct time zone on your computer. To select the time zone, click on the "Time Zone" button at the top of the "Date and Time" panel. Click on the world map to select the city nearest to your location or use the pop-up box to select the closest city to your location. When you've completed your date and time adjustments, close the "Date and Time" preference pane to save your settings.