ScheduledTask.ExpirationTime Property
July 26, 2012
Gets or sets the time at which the task’s schedule expires.
Assembly: Microsoft.Phone (in Microsoft.Phone.dll)
This date must be sometime after the current time, but must be 14 days or less from the current date. The default value is 14 days from the current date. Applications that use ScheduledTask must renew their schedule at least once every two weeks by calling Remove(String) and then Add(ScheduledAction) to add the task when the main application is running in the foreground. This helps to ensure that unused applications are not draining device resources.