Specifications

46 ExtremeWare XOS 10.1 Command Reference Guide
Commands for Accessing the Switch
Usage Guidelines
Network Time Protocol (NTP) server updates are distributed using GMT time. To properly display the
local time in logs and other timestamp information, the switch should be configured with the
appropriate offset to GMT based on geographic location.
The gmt_offset is specified in +/- minutes from the GMT time.
Automatic DST changes can be enabled or disabled. The default configuration, where DST begins on the
first Sunday in April at 2:00 AM and ends the last Sunday in October at 2:00 AM, applies to most of
North America, and can be configured with the following syntax:
configure timezone <gmt_offst> autodst.
The starting and ending date and time for DST may be specified, as these vary in time zones around the
world.
• Use the every keyword to specify a year-after-year repeating set of dates (for example, the last
Sunday in March every year)
• Use the on keyword to specify a non-repeating, specific date for the specified year. If you use this
option, you will need to specify the command again every year.
• The begins specification defaults to every first sunday april.
• The ends specification defaults to every last sunday october.
• The ends date may occur earlier in the year than the begins date. This will be the case for countries
in the Southern Hemisphere.
• If you specify only the starting or ending time (not both) the one you leave unspecified will be reset
to its default.
• The time_of_day specification defaults to 2:00.
• The timezone IDs are optional. They are used only in the display of timezone configuration
information in the
show switch command.
To disable automatic DST changes, re-specify the GMT offset using the noautodst option:
configure timezone <gmt_offst> noautodst.
NTP updates are distributed using GMT time. To properly display the local time in logs and other
timestamp information, the switch should be configured with the appropriate offset to GMT based on
geographical location. Table 5 describes the GMT offsets.
Table 5: Greenwich Mean Time Offsets
GMT Offset
in Hours
GMT Offset
in Minutes
Common Time Zone References Cities
+0:00 +0 GMT - Greenwich Mean
UT or UTC - Universal (Coordinated)
WET - Western European
London, England; Dublin, Ireland;
Edinburgh, Scotland; Lisbon, Portugal;
Reykjavik, Iceland; Casablanca, Morocco
-1:00 -60 WAT - West Africa Cape Verde Islands
-2:00 -120 AT - Azores Azores
-3:00 -180 Brasilia, Brazil; Buenos Aires, Argentina;
Georgetown, Guyana;
-4:00 -240 AST - Atlantic Standard Caracas; La Paz