This paper examines how dogs can modulate the effects of emotion on time perception. To this end, participants performed a temporal bisection task with stimulus durations presented in the form of neutral or emotional facial expressions (angry, sad, and happy faces). In the first experiment, dog owners were compared with nondog owners, while in the second experiment, students were randomly assigned to one of the three waiting groups (waiting alone, with another person, or with a dog) before being confronted with the temporal bisection task. The results showed that dogs allowed the participants to regulate the intensity of negative emotional effects, while no statistical differences emerged for the happy facial expressions. In certain circumstances, dogs could even lead the subjects to generate underestimation of time when faced with negative facial expressions.