Syntax:
NOW([fsp])

Returns the current date and time 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. The value is expressed in the current time
zone.

As of MySQL 5.6.4, if the fsp argument is given to specify a fractional
seconds precision from 0 to 6, the return value includes a fractional
seconds part of that many digits. Before 5.6.4, any argument is
ignored.

URL: http://dev.mysql.com/doc/refman/5.6/en/date-and-time-functions.html

