The Certina 28-351 watch movement, utilized between 1965 and present, incorporates various features including an electromechanically controlled balance motor, a back crown, a jumping sweep second, and an am/pm display by a dot below/above the date numeral. Moreover, the date can be adjusted by setting the hands back and forth, with each adjustment advancing the date by half a day. Care must be taken to ensure that the dot indicating day or night is aligned correctly. Furthermore, this movement includes an electrical and mechanical hack feature.