Unix timestamp is a system for representing dates and times as a single number, which is the number of seconds that have elapsed since January 1, 1970, at 00:00:00 UTC (Coordinated Universal Time).
The Unix timestamp is widely used in computer systems and applications to perform date and time calculations, to store dates and times in databases, and to track the duration between events.
To get the current Unix timestamp in PHP, you can use the time() function, like this: