DATETIME[(fsp)]

A date and time combination. The supported range is '1000-01-01
00:00:00.000000' to '9999-12-31 23:59:59.999999'. MySQL displays
DATETIME values in 'YYYY-MM-DD HH:MM:SS[.fraction]' format, but permits
assignment of values to DATETIME columns using either strings or
numbers.

As of MySQL 5.6.4, an optional fsp value in the range from 0 to 6 may
be given to specify fractional seconds precision. A value of 0
signifies that there is no fractional part. If omitted, the default
precision is 0.

As of MySQL 5.6.5, automatic initialization and updating to the current
date and time for DATETIME columns can be specified using DEFAULT and
ON UPDATE column definition clauses, as described in
http://dev.mysql.com/doc/refman/5.6/en/timestamp-initialization.html.

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

