A device that includes schedules activates the fast clock feature when the current date and time are changed in the device, the device restarts following a power failure or reset, or the device is put into simulation mode. The fast clock feature ensures the schedule and its associated scheduled items are in the correct state based on day and time of the device.
The fast clock evaluates the events scheduled for the current day from midnight to the current time, to find the last scheduled time and value for the current day. If the fast clock does not find any scheduled events, then the value associated with the latest time for the current day is used. Then the fast clock writes this value to all scheduled attributes of all items referenced by the schedule’s list of scheduled items.