Unix Timestamp

A unix timestamp (or Epoch Time) describes a point in time with the amount of passed seconds since the start of the Unix epoch at the 1 January 1970 00:00:00 UTC. The unix time differs slightely from UTC time, bacause leap seconds are ignored. Some programming alnguages also use milliseconds for the offset (like JavaScript's date.getTime()) or even nanoseconds.

Due to historical reasons, the unix timestamp is stored as signed 32-bit integer (to save memory). This results in the so-called year 2038 problem, when the overflow of the timestamp will happen at the 19 January 2038. Through this overflow, the system time will be the 13 December 1901, with will cause problems in some programms. Especially vunorable are legacy embedded systems and file systems or databases with with 32-bit time fields. To solve this problem, many modern systems use a 64-bit integer for the unix timestamp, with won't overflow as long as the universe will likely exist.

let timestamp = Date.now();

let date = new Date(timestamp);

let tsFromDate = date.getTime();