How UNIX_TIMESTAMP() Works in MariaDB

In MariaDB, UNIX_TIMESTAMP() is a built-in date and time function that returns a Unix timestamp, based on its argument (or lack of argument).

It works like this:

  • When called without an argument, it returns a Unix timestamp (seconds since ‘1970-01-01 00:00:00’ UTC) as an unsigned integer.
  • When called with an argument, it returns the value of the argument as seconds since ‘1970-01-01 00:00:00’ UTC.

The inverse function of UNIX_TIMESTAMP() is FROM_UNIXTIME().

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How TIMESTAMP() Works in MariaDB

In MariaDB, TIMESTAMP() is a built-in date and time function that returns a datetime value, based on its argument/s.

It can be used with either one argument or two, as follows:

  • When used with one argument, it returns that date or datetime expression as a datetime value.
  • When used with two arguments, it adds the second (time) argument to the first (date or datetime) expression, then returns the resulting datetime value.
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How TIMEDIFF() Works in MariaDB

In MariaDB, TIMEDIFF() is a built-in date and time function that returns the difference between two time values or datetime values, expressed as a time value.

It’s similar to the DATEDIFF() function, except that DATEDIFF()‘s return value is expressed in days.

TIMEDIFF() accepts two arguments, both of which are time or datetime expressions. It then subtracts the second time from the first.

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