Recent findings demonstrated that number magnitude affects the perception of display time (B. Xuan, D. Zhang, S. He, & X. Chen, 2007). Participants made fewer errors when display time (e.g., short) and magnitude (e.g., small) matched, suggesting an influence of magnitude on time perception. With the present experiment, the authors aimed to extend these findings by investigating whether number magnitude and time are also connected at the response level. Participants judged the parity of single digits by pressing a response key for either a short or a long duration. Responses were faster when small numbers required short keypresses and large numbers required long keypresses. In addition, overall keypress durations were affected by number magnitude. The results suggest a connection between number magnitude and time at the levels of response initiation and execution, thus supporting theories outlining a common magnitude system comprising time, space, and magnitude.