Abstract: The international time standard, coordinated universal time (UTC), is based on the Earth's rotation period. It uses the second—defined by the oscillation frequency of cesium atoms—as the basic unit of time and achieves synchronization with atomic time through the use of “leap seconds". Due to the increase in global average temperature, polar ice caps are melting, and sea levels are rising, which affects the Earth's rotation and leads to uncertainty in time synchronization. This article briefly introduces the development history of timekeepers, explains the necessity of unifying time standards and achieving time synchronization, and discusses the dynamic principles behind the impact of climate change on time synchronization.