A circuit for enabling the use of timing characterization data in a configurable light timer is described. The circuit comprises a connector adapted to receive a portable memory device having timing characterization data; a control circuit coupled to receive the timing characterization data; and a switch coupled between a reference voltage and an output terminal of the configurable light timer, wherein the switch is controlled by the control circuit to disconnect the reference voltage from the output terminal according to the timing characterization data. A method of enabling the use of timing characterization data in a configurable light timer is also disclosed.