Effort discountingdescribes the devaluation of rewards that require effort to obtain. The present study investigated whether discounting of cognitive effort depends on how near the effort is in time. The present study also investigated whether effort discounting, and its modulation by temporal distance to the effort, might depend onneed for cognition, a personality trait that describes how much one enjoys cognitively demanding tasks. Participants performed a validated effort discounting task that measured the extent to which they subjectively devalued a $20 reward when effort was required to receive it. Immediacy of the effort was manipulated by having participants imagine exerting varying levels of effort either immediately, in a day, or in a month. Results revealed linear increases in discounting of rewards as a function of both how much effort was involved and how imminent the effort was. The extent to which both these variables influenced discounting correlated with need for cognition. Individuals low in need for cognition exhibited more effort discounting overall and a linear increase in effort discounting as the effort grew imminent. Individuals high in need for cognition engaged in less effort discounting, which was not modulated by how imminent the effort was. These results indicate that people exhibit dynamic inconsistency in effort-related decisions, such that the degree to which they discount effort depends on how soon the effort is. Additionally, this tendency is linked with systematic individual differences in need for cognition. Lastly, this study demonstrates that these tendencies can be quantitatively operationalized.