in fact everybody has their own personal time or clock. the simple act or driving in a car or going up in an elevator changes your time from that of other peoples.
yeah, by an EXTREMELY minute & probably immeasurable amount..but..yeah...like, if two people, were born @ the SAME exact time, to the trillionths of a second, and you waited 10 years & gauged their age, to us, they'd both be 10, but, in terms of quantum physics & such, their age would differ because of their differing rates of movement through life