The most obnoxious problem resultant from interstellar travel is humanity’s need for a nuanced and contextual language to describe time. The most common solution is to define three types of standard years (8760 hours on a radioactive clock). Most star systems use a local standard year (LSY), 8760 hours spent moving at the speed of galactic expansion in a specific location other than Earth. A lived year is 8760 hours experienced by a person, and Earth standard year (ESY) is 8760 hours on Earth. Thus, when discussing age one might be 75 years old but born 750 ESYs ago.
How do you measure a year? Interstellar Chronologies.
100 Word Piece of Sci-fi Minutia