Cisco 7800 Series Administration Manual page 163

Parameter
Time Offset (HH/mm)
Ignore DHCP Time Offset
Daylight Saving Time Rule
Description
This specifies the offset from GMT to use for the local system time.
Default: 00/00
When used with some routers that have DHCP with time offset values
configured, the IP phone uses the router settings and ignores the IP
phone time zone and offset settings. To ignore the router DHCP time
offset value, and use the local time zone and offset settings, choose yes
for this option. Choosing no causes the IP phone to use the router's
DHCP time offset value.
Default: Yes.
Enter the rule for calculating daylight saving time; it should include the
start, end, and save values. This rule is comprised of three fields. Each
field is separated by ; (a semicolon) as shown below. Optional values
inside [ ] (the brackets) are assumed to be 0 if they are not specified.
Midnight is represented by 0:0:0 of the given date.
This is the format of the rule: Start = <start-time>; end=<end-time>;
save = <save-time>.
The <start-time> and <end-time> values specify the start and end dates
and times of daylight saving time. Each value is in this format: <month>
/<day> / <weekday>[/HH:[mm[:ss]]]
The <save-time> value is the number of hours, minutes, and/or seconds
to add to the current time during daylight saving time. The <save-time>
value can be preceded by a negative (-) sign if subtraction is desired
instead of addition. The <save-time> value is in this format:
[/[+|-]HH:[mm[:ss]]]
The <month> value equals any value in the range 1-12
(January-December).
The <day> value equals [+|-] any value in the range 1-31.
If <day> is 1, it means the <weekday> on or before the end of the month
(in other words the last occurrence of < weekday> in that month).
Cisco IP Phone 7800 Series for Third-Party Call Control Administration Guide
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