Final answer:
The setting used to add a date at the bottom of each page is the footer. The footer is found in word processing programs like Microsoft Word and is used to display information like dates on every page.
Step-by-step explanation:
The setting used to add a date at the bottom of each page in a document, such as a Microsoft Word document, is the footer. This area is typically used for page numbering, dates, and other information that appears at the bottom of every page. To insert the date into the footer, you would usually go into the Insert tab (in Word), select Footer, and then choose a style or edit the existing footer to add the date. This action automatically numbers pages and keeps the date current each time the document is opened.