The Unix time stamp is a way to track time as a running total of seconds. This count starts at the Unix Epoch on January 1st, 1970 at UTC. Therefore, the Unix time stamp is merely the number of seconds between a particular date and the Unix Epoch. This point in time does not change regardless of your location on the globe. This is very useful for computer systems for tracking and sorting dated information in dynamic and distributed applications both online and client side.
On this date, the Unix Time Stamp will cease to work due to a 32-bit overflow. Before this moment, millions of applications will need to either adopt a new convention for time stamps or be migrated to 64-bit systems, which will give the time stamp a "bit" more time.