Settings such as programmed events, minimum dim level, etc. are permanently programmed into the device. Power loss will not affect these settings and they will remain unchanged.
The DDS15, DDE06, DD710 and DDF01 all include a built-in backup battery that is used to keep track of the current time of day even in the event of a power loss. These devices have been designed to maintain the time for more than 72 hours without power.
The DDMX1 and DDL06-BL do not have a built-in backup battery, in the event of a power loss, may need to reconnect your device to the Decora Digital Dimmer & Timer.