Abstract: A time setting control mechanism mounted in a mechanical timer and driven to automatically start or stop a machine at a given time, including, a hollow time counting wheel, a dial mounted in the time counting wheel, the dial having a center through hole, a disk mounted between the time counting wheel and the dial and supported on the time counting wheel by springy projecting strips thereof, the disk having an upward flange raised around the periphery, and a press portion raised from the center and protruding over the center through hole on the dial for pressing by hand, and a time setting control pin detachably mounted on the periphery of the time counting wheel, the time setting control pin having a mounting base detachably coupled to the periphery of the time counting wheel, a springy hook extended from the mounting base and inserted into an annular space defined between the upward flange of the disk and the periphery of the dial and hooked on a bottom edge of the dial, and a trigger rod adapted for trigger