Echelon SmartServer 2.2 - Manual (Page 391)

392 Scheduling
2. Click Submit.
How the Scheduler Works with Daylight Savings Time
When daylight savings time starts, events scheduled in the switch hour are executed at the start of the
next hour. For example, if you have the following schedule in North America before DST:
1:59 ON
2:30 OFF
3:01 ON
It is executed as follows when DST starts (time switches from 02:00 to 03:00). Observe that the 2:30
OFF events occurs at 03:00.
1:59 ON
3:00 OFF
3:01 ON
When daylight savings time ends, events scheduled in the switch hour are executed only once, instead
of twice. For example, the following schedule in North America is executed as written when standard
time starts (time switches from 02:00 to 01:00). Observe that the events in 01:00 hour are only
executed once, even though that the hour occurs twice on that day.
12:59 STATE_3
1:15 STATE_1
1:45 STATE_2
2:01 STATE_3
Creating Sunrise and Sundown Events
You can create events in the exception schedule to occur at sunrise or sundown or a configured period
of time before or after. This is useful for controlling systems where the device behavior is determined
by the level of light (lux) such as street lighting, outdoor lighting, sun blinds, and sun shades. The
sunrise and sundown times are calculated by the astronomical position sensor application on the
SmartServer and then transmitted to the Event Scheduler. See the Configuring the Real-Time Clock
section earlier in this chapter for more detailed information on how the astronomical position sensor
functions.