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<concept id="GUID-FE2E8E58-6656-534E-A052-095AF559A482" xml:lang="en"><title>Alarm

Time Formats</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>The Alarm Server supports two types of time formats used to express the

expiry time of an alarm: </p>

<ul>

<li id="GUID-90BAC4D4-DD00-51D2-8661-51E2680DA315"><p> <b>Fixed time format</b> -

The alarm expires at the given UTC time and has no associated UTC offset.

The alarm is not rescheduled when an UTC offset or DST change occur. </p> </li>

<li id="GUID-A007966C-84AD-56E2-B692-7CAE4B3A648F"><p> <b>Floating time format</b> -

The alarm expires at the given local (wall clock) time in the current UTC

offset and are re-scheduled when either the UTC offset or DST change occurs. </p> </li>

</ul>

<p>The Alarm Server maintains a queue of alarms and the format of these alarms

may be either fixed or floating time format. </p>

<p>Hence, if the user adds an alarm defining one of its characteristics as <xref href="GUID-20A42BF7-A0F5-3177-9592-E3AE097B4CF2.dita#GUID-20A42BF7-A0F5-3177-9592-E3AE097B4CF2/GUID-EBAEFA64-7892-32D6-B8BF-EBE4EC9AFB83"><apiname>TAlarmCharacteristics::EAlarmCharacteristicsIsFixed</apiname></xref>,

then it is added in the alarm queue as fixed time format based alarm. </p>

<p> </p>

<p> <b>NOTE</b>: </p>

<ul>

<li id="GUID-14A58869-C859-5F7B-A28A-319F180DD8CE"><p> <b>UTC time</b> is

the non-secure system time in UTC (UTC time range is from 0-24, so after 12,

the time is expressed in PM). </p> <p> <b>Standard Time</b> = UTC Time + Timezone/UTC

offset </p> <p> <b>Wall Clock/local time</b> = UTC Time + Timezone/UTC offset

± DST offset </p> </li>

<li id="GUID-24513E63-880C-5147-9A5F-AFF047370175"><p>All alarms (irrespective

of the time format) undergo rescheduling and re-evaluation of their next due

time (considering their repeat definition) only when either system time/date

or workdays change. </p> </li>

<li id="GUID-80D105D4-D99D-56F3-9D92-11F7686FF3C1"><p>Only the floating time

format based alarms undergo re-scheduling and re-evaluation of their next

due time if the system time/date, workdays, UTC offset changes or DST rollover

event occurs. </p> </li>

</ul>