Editing Differslopedia:Selected anniversaries (section)

== "On this day" guidelines ==
The visible section of the selected anniversaries pages automatically rotates onto the Main Page each day to populate the '''"On this day"''' section. There is maintenance needed before each page appears which follow these guidelines:

* Generally 5 events out of those eligible can be chosen for display each day. This number may vary slightly depending on the length of the [[Wikipedia:Today's featured article]] and [[Wikipedia:Did you know]] sections so that the left and right columns appear balanced without too much empty space. Preference is given to entries celebrating a significant anniversary. For events 100 years old and up, that means multiples of 25 (e.g., 200th, 325th, 550th, etc.). If the event is less than 100 years old, that means multiples of 10 or 25 (e.g., 30th, 60th, 75th).
* Other considerations for choosing the entries to be shown can include the significance of the event; the mix of items to be listed in terms of years (e.g., not just limited to the 20th century), geographical areas (e.g., more than just the Anglosphere), and subjects (e.g., not too many articles on war or technology); the time since an item has last been shown; other events recently or shortly to be shown; the relative completeness of the article; and appropriate "context" (e.g., in a [[FIFA World Cup]] year, we may feature more football/soccer-related articles). Preference is ''not'' given to [[WP:good articles|good articles]] or even [[WP:featured articles|featured articles]] – all articles that meet the minimum standard should be considered with the same weight  (''see also {{section link|Wikipedia:FAQ/Main Page|I_think_that_the_articles_chosen_for_the_Main_Page_are_awful_and_much_more_important_articles_should_be_there_instead._Isn't_the_Main_Page_biased_towards_certain_topics?_What_can_be_done_about_it?}}'').
* [[Wikipedia:Selected anniversaries/Holidays and observances|Holidays/observances]] should be limited to a maximum of 3, but this may increase to accommodate those that do not appear on the same date each year. Holidays should be listed in this order: international observances (secular followed by religious) first (except those that are not serious in nature, e.g., [[International Talk Like a Pirate Day]]—these should appear at the end of the list), then alphabetically by country where observed. When the same day is observed in multiple countries (but not worldwide), then the countries should be listed alphabetically, and the first country used for sorting.
** Example (note that these are not actually all on the same date, but combined to demonstrate the sorting): '''[[Earth Day]]''' ({{CURRENTYEAR}}); '''[[Easter]]''' (Christianity, {{CURRENTYEAR}}); '''[[Mother's Day]]''' in Belize and Guatemala; '''[[Independence Day (United States)|Independence Day]]''' in the United States ([[1776]]); '''[[Star Wars Day]]'''
* To maintain a variety of topics on the Main Page, an event should not be chosen if it is also related to the subject of the [[WP:TFA|featured article]] or the [[WP:POTD|featured picture]] for that particular day.
* For births and deaths, when possible try to follow the same rules of thumb: include both births and deaths, include male and female entries, and maintain chronological/geographical/topical diversity.
* Only one image/video/audio file should be displayed for any particular day.
* Non-[[Gregorian calendar|Gregorian]]-based holidays and observances should be moved to the correct day for the current year. When moved, they should not count towards the maximum "3&nbsp;holidays/observances per day" limit since a number of them might suddenly fall on the same day during a particular year.<ref group=nb>See, for example, [http://en.wikipedia.org/w/index.php?title=Wikipedia:Selected_anniversaries/March_20&oldid=199502353] and [http://en.wikipedia.org/w/index.php?title=Wikipedia:Selected_anniversaries/February_14&oldid=343501397].</ref> These holidays and observances should also be marked with the current year in parentheses as an indicator to readers that observance on this day is specific to this year. Certain non-Gregorian holidays may appear more than once per calendar year due the differences between calendars (most notably Jewish or Islamic holidays).
* In general, [[National Day]]s, [[Independence Day]]s, and other holidays celebrating the [[nation]]hood of a [[country]] should be marked by the year of the significant historic date being observed. An exception can be made when non-Gregorian-based holidays also fall within the same day, and the non-consistent use of dates might confuse new readers.<ref group=nb>As per [http://en.wikipedia.org/w/index.php?title=Wikipedia:Main_Page/Errors&diff=prev&oldid=125492269 this post] on WP:ERRORS.</ref>
* Each boldfaced article should be checked to make sure it still qualifies under the [[#Selected anniversaries criteria|selected anniversaries criteria]] above. For those that do not, there are two options: an alternate boldfaced article can be chosen for the same event if one exists, especially if the original boldfaced article was [[WP:MERGE|merged]] or [[WP:SS|split]]. Otherwise, it should be moved to the 'ineligible' section of the [[#Purpose of the staging area|staging area]] with a note indicating the improvements needed.
* Make sure to double check, copyedit, and verify each event chosen so it is consistent with the facts presented in the boldfaced article because they may have changed since the previous year.<ref group=nb>As per [https://en.wikipedia.org/w/index.php?title=Wikipedia:Selected_anniversaries/February_4&diff=763531506&oldid=763529397 this example.]</ref>
* After making changes, please edit the talk page to indicate what changes were made, following the examples that are already there.

=== When guidelines conflict ===
Generally speaking, please apply the guidelines in the following order to determine which items to include:
# Give precedence to significant anniversaries (multiples of 100 get the top priority, followed by multiples of 50, while 25 and 10 can be considered equal)
# Maintain chronological diversity
# Maintain geographic diversity
# Maintain topic diversity
# Avoid using similar blurbs that are within ±3 days

However, there are times when several of these will come into conflict with each other. For example, on one day in one year, we might have three items that are having their 70th, 75th, and 80th anniversaries respectively, which conflicts with the guideline for chronological diversity. In these cases, please use your best judgement as to how to balance them. So in this hypothetical scenario, maybe one of the three items also featured last year, so you could leave that one out this year. Or maybe two of items are battles in the same war (or two are in the same country), so you could omit the one that appeared more recently. Unfortunately, there is no algorithm that will guarantee that we always have an ideal set of blurbs, so a compromise will have to be made somewhere. As long as you make a carefully considered decision, it will be fine.