Abstract: An adjustable cycle timer that controls on and off cycling of a livewell bait pump or similar device. The on time and off time of the cycle are each independently variable by adjusting the frequency of frequency generators, one generator (10) for on time and one generator (14) for off time in the cycle. The outputs of these frequency generators are gated to the clock input of a frequency divider (20), the output of which controls a relay driver (30) or similar device that switches the pump motor or other device to be controlled. When the output (22) of the frequency divider (20) changes state, a feedback switching circuit (29) blocks the output of one of the frequency generators, and gates the output of the other frequency generator to the input of the frequency divider (20). This allows the length of the on time segment of the cycle to be controlled by the frequency of one of the frequency generators, while the length of the off time segment of the cycle is controlled by the other frequency generator.