In English, the abbreviations "y" or "yr" are more commonly used in non-scientific literature. In some Earth sciences branches (geology and paleontology), "kyr, myr, byr" (thousands, millions, and billions of years, respectively) and similar abbreviations are used to denote intervals of time remote from the present. In astronomy the abbreviations kyr, Myr and Gyr are in common use for kiloyears, megayears and gigayears.
in english the abbreviations "y" or "yr" are more commonly used in non-scientific literature in some earth sciences branches (geology and paleontology) "kyr myr byr" (thousands millions and billions of years respectively) and similar abbreviations are used to denote intervals of time remote from the present in astronomy the abbreviations kyr myr and gyr are in common use for kiloyears megayears and gigayears