Per Albert Einstein’s research, time is theorized to be regularly altered by the gravitational pull of matter. Time dilation affects all things depending on their distance from a body’s center of mass. According to the Hafele-Keating experiment, even the precision of atomic clocks can be distorted by this effect. In the study, clocks were placed aboard separate airliners and flown around the world. Upon their return, it was found that both clocks — despite having initially been in sync — were running at separate speeds after traveling at varying altitudes (via The Vintage News). 

Practically, the difference made by time dilation is not noticeable outside of using time-keeping devices to record its effects. Yet, the fact that it does technically exist and is measurable can have drastic consequences for how science progresses (i.e. the need for GPS software to compensate for it, per The Science Explorer). If in the future, astronauts begin to spend longer periods of time in space, the effects of time dilation may lead to more substantial changes in how they perceive time (via Scientific American).