Using the command line interface (CLI) : execute : execute date
 
execute date
The execute date command allows you to get or set the system date. If you do not specify a date, the command returns the current system date.
Syntax
execute date [<date_str>]
where:
Variable
Description
<date_str>
This variable has the form mm/dd/yyyy.
mm is the month and can be 01 to 12
dd is the day of the month and can be 01 to 31
yyyy is the year and can be 2001 to 2100
Dates entered will be validated - mm and dd require 2 digits, and yyyy requires 4 digits.
Example
To set the date to 17 September 2013:
execute date 09/17/2013
See also
Setting the system time