Editing of alarms is not supported. In scenarios when you want to edit an alarm, remove the original alarm and add a new updated alarm. However, the following alarm properties can be updated:
Characteristics of an alarm (TAlarmCharacteristics) - The characteristics are updated, and these are used to determine whether the client is still notified when an alarm expires, and whether the alarm dialog is displayed when an alarm expires.
DayOrTimed - It indicates whether the alarm is associated with a day or a timed appointment. The default is Timed. This property is ignored by Alarm Server, and is for the client’s use only.