The duration of action can be critical to accomplishing specific goals. Empirical findings and theoretical considerations suggest that different stages of action planning and execution require different specification levels of action features. It is assumed that at first only crude categorical features are integrated into action plans, which are then specified by subsequent sensorimotor processes during action execution based on situational conditions. In two experiments, we investigated if the integration of action duration into action plans indeed relies exclusively on categorical duration representations or also on continuous-metric representations. Participants responded to visual prime and probe stimuli with short and long key presses. The duration of the prime response was indicated by a previous response cue, and the duration of the probe response was indicated by the shape of the probe stimulus. Analyses of response durations revealed that for response category repetitions from prime to probe, the actual durations of the repeated responses were more similar for shape repetitions than for shape switches. This indicates that continuous temporal information is integrated into an action plan and subsequently retrieved by stimulus repetition. Our results suggest that action duration is integrated into the action plan in a relatively precise form at an early stage of action planning.