The second component in a reference is the date. Most citations only need the year in parentheses, followed by a period.
Author. (Date). Title. Source.
Source: Publication Manual, 9.13-9-17; APA Style: Elements of Reference List Entries; APA Style: Missing Reference Information
Most sources (such as books, journal articles, and films) only require the year. For magazines, newsletters, newspapers, social media, YouTube videos, blog posts, etc., provide the full date.
Valinsky, J. (2019, October 8). Instagram dark mode is here. CNN. https://www.cnn.com/2019/10/08/tech/instagram-dark-mode-trnd/index.html
In-text citations, however, will only include the year.
(Valinksy, 2019)
If an item does not have a discernible date, you may use n.d. as the date (for no date); do not simply leave out the date. For webpages, do not use a general copyright date given for the website. Look for a specific created, updated, or modified date for the page or document you are using.
Santa Fe College. (n.d.). Fifty years to first. https://www.sfcollege.edu/about/50/
(Santa Fe College, n.d.)
If you have two or more distinct works by the same author and published in the same year, differentiate them with letters. Organize these references by the title element.
Rowling, J. K. (1999a). Harry Potter and the chamber of secrets. Arthur A. Levine.
(Rowling, 1999a)
Rowling, J. K. (1999b). Harry Potter and the prisoner of Azkaban. Arthur A. Levine.
(Rowling, 1999b)
For items that have a full date, such as blogs or newspaper articles, add the differentiating letter to the year, and keep the month and/or day. Recall that only years are included in an in-text citation. Organize them in the references list by date.
Flaherty, C. (2018a, March 14). Same course, different ratings. Inside Higher Ed. https://www.insidehighered.com/news/2018/03/14/study-says-students-rate-men-more-highly-women-even-when-theyre-teaching-identical
(Flaherty, 2018a)
Flaherty, C. (2018b, April 12). Diversifying a classic humanities course. Inside Higher Ed. https://www.insidehighered.com/news/2018/04/12/responding-student-criticism-its-foundational-humanities-course-too-white-reed
(Flaherty, 2018b)
If both items are using n.d. instead of a year, include a hyphen before the differentiating letter. Organize these references by the title element.
Santa Fe College. (n.d.-a). Honors student code of conduct. https://www.sfcollege.edu/honors/honors-student-code-of-conduct/index
(Santa Fe College, n.d.-a)
Santa Fe College. (n.d.-b). Priority admissions dates. https://www.sfcollege.edu/admissions/priority-admissions-dates/index
(Santa Fe College, n.d.-b)
If you are citing a classic work that has been reprinted or republished, you can include the original date at the end of the reference. Include both dates in the in-text citation.
Freud, S. (2005). Civilization and its discontents. Norton. (Original work published 1930)
(Freud, 1930/2005)
If the resources you are citing may change substantially before readers can access it, you may add a retrieval date prior to the URL. Examples include wikis, dictionary entries, Twitter profiles, webpages that update frequently, etc.
Centers for Disease Control and Prevention. (2019, October 3). Outbreak of lung injury associated with e-cigarette use, or vaping. Retrieved October 8, 2019, from https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html
(Centers for Disease Control and Prevention, 2019)