While the structure of simple decision making is well described as the noisy accumulation of evidence over time, the influence of subjective preferences in deliberation remains underexplored. Here, I show how reference dependence based on expected time use can affect deliberative time allocation. In a motion discrimination task, I provide some participants with an indication of how long the block will take to complete. Once they exceed this benchmark, they spend less time accumulating information, at the expense of foregone rewards. By incorporating reference dependence into the drift diffusion model, I quantify the impact of the reference point on preferences directly. Moreover, I uncover the time course of preferences by estimating the subjective value of time in a sliding window. Thus I provide novel evidence on the impact of temporal reference points, and illuminate the role of subjective preferences in deliberative behavior.