Insert Header & Footer
8. Insert the Header
& Footer
Go to
View ->Slide Master.
Select the Text Master from the list.
Go to
Insert -> Header & Footer.

What Do You See? The Date and Time gets
it's own text box. The Date/Time field can automatically update. The
Footer is a separate text box you can check on and add sample
text.
In this example the information was placed at the top
of the slide. That's a header and part of the theme that was
applied to this slide. When the text box is placed on the bottom,
that's a footer. Makes sense to me.