Final answer:
It is false to claim that the Roman Empire did not impose its calendar on other nations; due to the empire's power and the calendar's practicality, the Julian calendar saw widespread adoption. Greece, unlike Rome, did not have centralized control to enforce such an imposition.
Step-by-step explanation:
It is false that the Roman Empire did not impose their calendar on other cultures; rather, the Julian calendar and its later refinements became widely used throughout the Roman Empire due to its administrative convenience and the empire's significant influence. The Romans did not force their cultural practices and religious beliefs as aggressively as some empires, often allowing a degree of autonomy to the local traditions of conquered peoples. They did mandate some elements of Roman culture, however, such as architectural styles, political structures, and indeed standardized measurements including time-keeping, which would involve the calendar.
The Roman Empire's adoption of the Julian calendar was significantly impactful due to the empire's vast reach. This calendar became the dominant time-keeping system, influencing nations long after the fall of Rome and was only later modified substantially to become the Gregorian calendar used today. The empire's power and the efficiency of the Julian calendar facilitated its widespread adoption.
Greece, on the other hand, did not exert the same level of direct control or imposition of culture and systems onto others, as it was more a collection of city-states (poleis) rather than a single monolithic entity. Greek influence spread largely through colonization, trade, and the cultural appeal of Hellenism during the Hellenistic period following the conquests of Alexander the Great, not by forced imposition of Greek systems.