The Model of Action Phases (Gollwitzer, 1990, 2012) distinguishes an implemental mindset evoked by planning goal-directed actions, from a deliberative mindset evoked by pondering pros/cons of adopting a particular goal. The present research demonstrates that mindsets affect time predictions. In Study 1 (N = 151), participants in an implemental mindset made shorter time predictions with respect to completing personal goals than participants in a deliberative mindset. In Study 2 (N = 78), we tested a mediating mechanism for the mindset effect by varying the motivation to return a report. The mindset effect was replicated in the low- but not in the high-motivation condition with participants in an implemental mindset returning the report earlier, and being as accurate in their predictions as participants in a deliberative mindset. Results indicate that an implemental (vs. deliberative) mindset increases motivation and therefore leads to shorter, but equally biased time predictions.