We focus on the strategic implications of executive time horizons on a top management team. We argue that time horizon mean and diversity individually and interactively influence organizational ambidexterity, that is, a firm’s joint exploitation of current competencies and exploration of new opportunities. Drawing on the chief executive officer and top management team interface literature, we propose that effective CEO temporal leadership will enhance the joint effects of top management team time horizon mean and diversity on organizational ambidexterity. We tested our hypotheses by conducting multiple runs of surveys on a sample of 146 Chinese small- and medium-sized firms. Our study contributes to upper echelons theory and temporal research on strategy, being the first to examine the strategic consequences of top management team time horizon composition.