   FROM_UNIXTIME(unix_timestamp)
   FROM_UNIXTIME(unix_timestamp,format)
Returns a representation of the unix_timestamp argument as a value in
'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS format, depending on
whether the function is used in a string or numeric context.

mysql> SELECT FROM_UNIXTIME(875996580);
        -> '1997-10-04 22:23:00'
mysql> SELECT FROM_UNIXTIME(875996580) + 0;
        -> 19971004222300

If format is given, the result is formatted according to the
format string. format may contain the same specifiers as
those listed in the entry for the DATE_FORMAT() function.
