People use space to conceptualize time, but the specifics of the space-time mappings in people’s minds vary across cultures. Here we investigated whether people with different reading and writing systems in their native languages think about time differently, and whether exposure to a new language and culture changes people’s space-time mappings. We analyzed the spontaneous hand gestures that people made while telling stories about the past and the future and compared these gestures across three groups: Spaniards living in Spain, Moroccans living in Spain, and Moroccans living in Morocco. Whereas Spanish is written from left to right, Moroccan Arabic is written from right to left. Consistent with previous studies linking temporal thinking with reading and writing habits, we found that Spaniards showed a statistically significant bias to gesture leftward for earlier times and rightward for later times. Moroccans showed the opposite bias, gesturing rightward for earlier times and leftward for later times; this pattern did not differ significantly between the Moroccans living in Morocco (who were speaking Moroccan Arabic during the test) and the Moroccans living in Spain (who were speaking Spanish during the test). Together, these results support that hypothesis that people’s mental timelines follow the direction of reading and writing in their native languages, and that these culture-specific space-time mappings can be maintained despite immersion in a second language and culture.