UnixTime (sometimes called epoch time) is the number of seconds since midnight on new years day 1970. It is often used to encode dates in a nice way for computers to calculate with, avoiding all the problems surrounding the formatting associated with human requirements, e.g. DD/MM/YY, MM/DD/YY, YYYY etc. It is often used as a batch number for processes as it results in a unique number but implictly it carries the date when it was processed, but beware: It is not infallible.

Incidentaly, the time now (07/12/2023 06:37:04) is 1701931024 in UnixTime.