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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
OL-10101-02
Chapter 7 Administering the Switch
Managing the System Time and Date
Configuring Time and Date Manually
If no other source of time is available, you can manually configure the time and date after the system is
restarted. The time remains accurate until the next system restart. We recommend that you use manual
configuration only as a last resort. If you have an outside source to which the switch can synchronize,
you do not need to manually set the system clock.
This section contains this configuration information:
• Setting the System Clock, page 7-11
• Displaying the Time and Date Configuration, page 7-11
• Configuring the Time Zone, page 7-12
• Configuring Summer Time (Daylight Saving Time), page 7-12

Setting the System Clock

If you have an outside source on the network that provides time services, such as an NTP server, you do
not need to manually set the system clock.
Beginning in privileged EXEC mode, follow these steps to set the system clock:
This example shows how to manually set the system clock to 1:32 p.m. on July 23, 2001:
Switch# clock set 13:32:00 23 July 2001

Displaying the Time and Date Configuration

To display the time and date configuration, use the show clock [detail] privileged EXEC command.
The system clock keeps an authoritative flag that shows whether the time is authoritative (believed to be
accurate). If the system clock has been set by a timing source such as NTP, the flag is set. If the time is
not authoritative, it is used only for display purposes. Until the clock is authoritative and the
authoritative flag is set, the flag prevents peers from synchronizing to the clock when the peers’ time is
invalid.
The symbol that precedes the show clock display has this meaning:
• *—Time is not authoritative.
• (blank)—Time is authoritative.
Command Purpose
Step 1 clock set hh:mm:ss day month year
or
clock set hh:mm:ss month day year
Manually set the system clock using one of these formats.
• For hh:mm:ss, specify the time in hours (24-hour format), minutes,
and seconds. The time specified is relative to the configured time
zone.
• For day, specify the day by date in the month.
• For month, specify the month by name.
• For year, specify the year (no abbreviation).
Step 2 show running-config Verify your entries.
Step 3 copy running-config startup-config (Optional) Save your entries in the configuration file.