Abstract: A timing device of the flowing medium type that allows for multiple timing periods and for instant resetting capabilities whether the timer is in a timing sequence or is at rest. The timer is so constructed that specified 90.degree. or 180.degree. revolutions of the unit instantly combine all the timing medium, divide the timing medium by causing it to fall onto dividing baffles and then into separate reservoirs, activate the selected timing mode, or interrupt the timing process. The timing sequence of the timer may be interrupted at any time and be immediately reset to begin the same sequence again or to start a sequence of a different time duration by making the proper revolution of the timing device.