A user interface of a configurable light timer is described. The user interface comprises an input portion for receiving timing characterization data, the input portion adapted to receive a portable memory device storing the timing characterization data; a control circuit coupled to detect the portable memory device inserted into the configurable light timer; and an internal memory; wherein the timing characterization data is automatically downloaded to the internal memory after the portable memory device is detected in the configurable light timer. A method of implementing a configurable light timer is also disclosed.