UNIX_TIMESTAMP usage of mysql

UNIX_TIMESTAMP is generally used for unix timestamps.

example:

SELECT UNIX_TIMESTAMP("2016-07-11")
-- 1468166400
SELECT UNIX_TIMESTAMP("2016-07-17 23:59:59")
-- 1468771199

FROM_UNIXTIME: Indicates that UNIX_TIMESTAMP is restored to the standard time format

SELECT FROM_UNIXTIME(1468166400),FROM_UNIXTIME(1468771199)