6.2 Managing the System Clock
The switch uses the system clock for displaying the time and time-stamping messages. The system clock is set to Coordinated Universal Time (UTC). The switch calculates local time based on the time zone setting. Time-stamps and time displays are in local time.
6.2.1 Configuring the Time Zone
The time zone setting is used by the switch to convert the system time (UTC) to local time. To specify the time zone, use the clock timezone command.
These commands configure the switch for the United States Central Time Zone.
switch(config)#clock timezone US/Central
switch(config)#show clock
Mon Jan 14 18:42:49 2013
timezone is US/Central
To view the predefined time zone labels, enter clock timezone with a question mark.
switch(config)#clock timezone ?
  Africa/Abidjan                    Africa/Accra
  WET                               WET timezone
  Zulu                              Zulu timezone
switch(config)#clock timezone
This command displays all time zone labels that start with America.
switch(config)#clock timezone AMERICA?
America/Adak                    America/Anchorage
switch(config)#clock timezone AMERICA
6.2.2 Setting the System Clock Manually
The clock set command manually configures the system clock time and date, in local time. Any NTP servers properly configured on the switch override time that is manually entered.
This command manually sets the switch time.
switch#clock set 08:15:24 14 Jan 2013
Mon Jan 14 08:15:25 2013
timezone is US/Central
6.2.3 Displaying the Time
To display the local time and configured time zone, enter the show clock command.
This command displays the switch time.
switch(config)>show clock
Mon Jan 14 16:32:46 2013
timezone is America/Los_Angeles