Unless you manually edit them, the dates and times you type or insert into your Word documents are literally set in stone. If you use the "Update automatically" option with Word's Date and Time tool, however, the dates you insert will be automatically updated every time your document is opened.
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Click your mouse at the location within your document where you want to insert the date. You can add the date to the body of your document, the header or in the footer section.
Click the "Insert" ribbon tab, then "Date & Time" in the Text group.
Select the date format you need from the available formats. For example, you can choose the date with the day name included, short dates or both the date and time.
Select the check box labeled "Update automatically," then click "OK." After you close the document, Word will display the current date the next time you open it.