Daylighting control photocell sensors (CES\I, CES\O, CES\A and CES\S) and the CCLK-1004 photocell controller provide indoor, outdoor, or skylight control of lighting circuits based on natural daylight. The sensors and controller are able to provide coverage for any application. The photocell sensors light level measurements to an analog signal that is sent to Cristal room controller (CCLDIM) or the astronomical time clock (CCLK-1004) control module to control area lighting by switching banks of lights on and off or with 0-10V dimming. The sensors are factory calibrated, and sensitivity is adjustable through the control module. The indoor sensor has a flat Fresnel lens that looks downward in a 60-degree cone of reference to measure actual light on the work surface. The outdoor sensor is enclosed in a weatherproof housing with a visor for shading and lens protection. The Atrium and Skylight sensors both use diffusing dome lenses to provide a 180-degree angle of photodiode response.