Since the early works on the importance of time as a source of competitive advantage, there has been notable promotion across the strategic management and work-life balance literatures of increased temporal flexibility. More recently, these areas of study have suggested temporal flexibility as a panacea for environmental uncertainty. Careful study of those literatures, however, makes clear that flexibility means something different in each of those literature streams, predominately reflecting the self-interests of employers in the strategic management literature and the self-interests of employees in the HRM and related work-life balance literatures. Using longitudinal data found in the 1997 and 2002 National Surveys of the Changing Workforce, this study seeks to clarify the temporal flexibility needs of the parties engaged in the social exchange of work. It is also designed to explore statistical associations between each form of those needs and the extension or withholding by employees of key discretionary, pro-organizational behaviors.