The CT03 timer is a low-cost microprocessor-based device for time sequence control with 2 adjustable time periods forming a time cycle, 3 sub-ranges, and 4 different timing modes. The push-wheel switch (BCD) on the front panel enables easy setting of the period duration and the 3-digit display indicates the current time, the parameters, or the operating mode. All modes of operation and parameters are user-programmable via front-panel keyboard. CT03 is also equipped with 2 contact inputs for external start and hold and 2 output relays with programmable action for timing control of processes through switching electrical actuators on and off. The extended features of CT03 simplify programming and process monitoring and make the timer a convenient solution to a wide range of timing related problems.