Past studies have shown that concepts related to the past are associated with left-side responses, whereas concepts related to the future are associated with right-side responses, which is called the space-time compatibility (STC) effect. Some researchers have considered the direction of habitual reading and writing as the origin of this compatibility effect. However, the hypothesis was supported from the evidence across different cultures, but lack of the evidence within a culture. Our goal of the study is to investigate whether orthography influence implicit spatial representations of time independent of other cultural and linguistic factors. Using the time discrimination task, two behavior experiments were conducted for this purpose. A total of 20 180-degree rotated (Experiment 1) or mirror-reversed (Experiment 2) time-related words were given, half of them referring to past time and the other half referring to future time. In the time discrimination task, participants were asked to decide whether the word referred to the past or the future by pressing A or L on the keyboards of the computer. The reaction time of participants were recorded and analyzed with repeated measure MANOVA. The results of experiment 1 indicated that there was a clear interaction between time-related words and response location. Participants’ responses were faster when past and future time were mapped onto left and right keys, respectively, than when the opposite mapping was used. The results in experiment 2 indicated that there was also a clear interaction between time-related words and response location. Participants were faster responding to past words with the right hand and to future words with the left hand. The pattern of results in experiment 2 was opposite to the pattern of results in experiment 1. The opposite pattern of reaction times in the mirror-reversed condition was consistent with those results found previously in native Arabic and Hebrew speakers. In conclusion, our results suggest that people activate implicit associations between spatial representation and temporal representation when processing temporal language, and that the specifics of these associations could vary systematically within a culture. These results demonstrate a causal role for writing direction in shaping implicit mental representations of time.