A photocontrol controls the activation of lighting based on ambient light
and the time of day using a radio-controlled timer. Radio signals from a
particular source of correct time, such as the National Institute for
Science and Technology's WWVB radio broadcast, carry encoded time
information that can be decoded by the photocontrol to ascertain the
current time on start up and periodically during operation. The correct
date and time information is used to synchronize the photocontrol's
internal clock so that it can turn the lighting load off or on at
specific times of the day in accordance with the user's needs. Thus area,
business signage, and security lighting, for example, can be turned off
late at night and then back on early in the morning to reduce energy
consumption by the lighting during those hours when the lighting is not
needed.