Floating timeline

A floating timeline (also known as a sliding timescale) is a device used in fiction, particularly in long-running comics and animation, to explain why characters age little or not at all while the setting around them remains contemporary to the real world. The term is used in the comics community to refer to series that take place in a "continuous present". Floating timelines are also used when creators do not need or want their characters to age, typically in children's books and animated television shows.