Sometimes sources, especially webpages, will not have an identifiable publication date. Fortunately, style manuals provide instructions on what to do in these cases! Remember: When citing sources, you need both the full citation/reference and the in-text/parenthetical citation. Below are examples from three popular style manuals.
MLA
If there's no date, MLA recommends that you add the date you accessed the webpage at the end of each citation.
Examples
Work Cited: . . . Accessed 10 Jan 2019.
In-Text Citation: (Last Name of Author, pg #).
APA
When citing webpages, make sure that the copyright date applies to the content you're citing. APA does not want you to use the copyright date in the webpage footer. If there's a "last updated" or "revised date," use that date. Otherwise, cite the source as having no date. Use "n.d" for no date.
Examples
Reference: Miller, A. (n.d.).
In-Text Citation: (Miller, n.d.) or Miller (n.d.).
CSE
When there's no date, include the words "date unknown" within square brackets.
Reference: Miller A. [date unknown].
In-Text Citation: (Miller [date unknown]).
