Wikipedia:Selected anniversaries

This page in a nutshell: There are a variety of ways in which editors can contribute to the Selected anniversaries project. The deciding criteria in what gets posted to the "On this day" section of the Main Page each day are NOT solely based on what are "the most important or significant" anniversaries on this day. This is due to the fact that any given day of the year can have a great many historically significant events all eligible to be included, and because relative article quality, along with the mix of topics listed, are also considered.

Shortcut WP:OTD

This set of pages serves as a queue of selected anniversaries which populate the section of the Main Page each day. These pages are also used to help facilitate and coordinate updates to this queue. The selected anniversaries are taken from events in history on each day of the year and holidays/observances from current lunar-based calendars including Jewish, Islamic, and others.