Changing Table Structures - Mastering phpMyAdmin 2.8 for Effective MySQL Management - page 91

Small symbols on each side of the month and year headers permit easy scrolling
through months and years, and a simple click on the date we want transports it to
our date_published field.
For a DATETIME or TIMESTAMP field, the popup offers to edit the time part:
TIMESTAMP Options
Starting with MySQL 4.1.2, there are more options that can affect a TIMESTAMP
column. Let's add to our topics table a column named stamp of type TIMESTAMP .
As soon as we choose TIMESTAMP from the Type drop-down list - provided that
JavaScript has been activated in our browser - we see a new checkbox under the
Default column: CURRENT_TIMESTAMP . Note that in the Attributes column, we
can choose ON UPDATE CURRENT_TIMESTAMP .