Daylight Saving Time - Linksys SPA921-NA Administrator's Manual

System Administration
The time served by the NTP Server and the SIP Date Header are expressed in GMT time. The
local time is obtained by offsetting the GMT according to the time zone of the region. The
<Time Zone> parameter can be configured from the web page or through provisioning. This
time can be further offset using the <Time Offset (HH/mm)> parameter, which must be entered
in 24-hour format. This parameter can also be configured from the LCD display. The <Time
Zone> and <Time Offset (HH/mm)> offset values are not applied to the manual time/date
setup.

Daylight Saving Time

The 900 Series phone supports auto adjustment for daylight saving time. To enable this feature,
the administrator must configure the <Daylight Saving Time Rule> parameter on the Regional
tab. This parameter is a rule with three fields separated by semicolon (;) as shown below:
start=<start-time>;end=<end-time>;save=<save-time>
Where:
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<start-time> and <end-time> specify the start and end time and date of daylight saving time
and <save-time> is the amount of hour/min/sec to add to the current time during daylight
saving period.
The <save-time> value can be preceded by a negative (-) sign if subtraction is desired instead
of addition. If <weekday> is 0, it means the date to start or end daylight saving is at exactly the
given date. In that case, the <day> value must not be negative. If <weekday> is not zero, then
the daylight saving starts or ends on the <weekday> on or after the given date if <day> is
positive, or on or before the given date if <day> is negative. 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).
Optional values inside [ ] are assumed to be 0 if they are not specified. Midnight means 0:0:0
of the given date.
The following example configures daylight savings time for the U.S, adding one hour starting
at midnight on the first Sunday in April and ending at midnight on the last Sunday of October:
start=4/1/7/0:0:0;end=10/31/7/0:0:0;save=1
start=4/1/7;end=10/-1/7;save=1
start=4/1/7/0;end=10/-1/7/0;save=1
The following example configures daylight savings time for Egypt, starting at midnight on the
last Sunday in April and ending at midnight on the last Sunday of September:
Linksys 900 Series IP Phone Administrator Guide
3-28
<start-time> and <end-time> are of the form: <month>/<day>/<weekday>[/HH:[mm[:ss]]]
<save-time> is of form: [/[+|-]HH:[mm[:ss]]]
<month> = 1,2,12 (for Jan, Feb, Dec)
<day> = [+|-]1,2,3,...,,31
<weekday> = 1, 2, 3,..., 7 (for Mon, Tue, ..., Sun), or 0 which has special meaning
HH = hour (0-23)
mm = minute (0-59)
ss = second (0-59)
Chapter 3 Managing Linksys 900 Series IP Phones
Document Version 3.0