Wikipedia:Overview of date formatting guidelines

Wikipedia has guidelines for formatting dates (MOS:DATEFORMAT), divided into various sections. They set out the acceptable date formats that may be used in Wikipedia articles, namely:

• Day–month–year (DMY) format—e.g., 8 June 2025 or 8 Jun 2025;
• Month–day–year (MDY) format—e.g., June 8, 2025 or Jun 8, 2025;
• Year–month–day (YMD) format—e.g., 2025-06-08—only used in references and places where space is limited (e.g., tables), not in prose.

The guidelines provide additional guidance on deciding which format should be used in particular cases. It can sometimes be confusing to understand which sections to apply in particular cases. The priority between these provisions can be summarised as follows:

1. Consistency (MOS:DATEUNIFY): Each article should use either DMY or MDY format consistently, except access/archive dates (and in some cases publication dates) in references may use YMD-formatted dates.
2. Strong national ties to a topic (MOS:DATETIES): Articles on topics with strong ties to a particular English-speaking country should generally use the date format most commonly used in that nation. This generally means:
   • Articles on US topics use MDY format, except articles on modern US military topics use DMY in line with modern military usage;
   • Articles on Canadian topics may use either DMY or MDY;
   • Articles on topics relating to other English-speaking countries use DMY.

   There may be other exceptions for particular topic areas.

3. Retaining existing format (MOS:DATERET): If an article has evolved using predominantly one format, don't change it unless:
   • to conform with strong national ties (in accordance with MOS:DATETIES, as discussed in 2 above); or
   • there is consensus on the article's talk page otherwise (see below).

As is the case with any guidelines, occasional exceptions will apply to the guidelines outlined above. If there are good reasons to ignore the guidelines in particular cases, use common sense and discuss any proposed deviation from the guidelines on the relevant talk page for an article to reach consensus.

Caution should be used before making changes to the established date formats of existing articles, especially changes to multiple articles in a particular subject area. Consider whether the proposed change would improve Wikipedia and whether editors who have contributed to the articles on a particular subject may have reached a consensus to use a particular format. Some editors may revert changes to date formats that are made without prior discussion, even when those changes cite appropriate sections of the guidelines supporting them.