WhatHappenedTodayInHistory.com is a historical reference website that helps visitors discover notable events associated with any date. Its database contains more than 105,060 records drawn from Wikipedia, covering events from 3761 BC to the present. The site presents history as a chronological record of significant events and invites users to explore the facts and stories connected with a particular day.

Visitors can browse events for the current date or select a month and day, with the option to enter a year for a more specific search. Results use dates from the Gregorian calendar, and the website also offers full-year calendars for any year. Alongside historical entries, date pages may include calendar details such as the day of the year, days remaining, weekday, zodiac sign, and birthstones. The site features examples of events from across different periods, including political, military, cultural, and social history. It also provides links for sharing or directly linking to a page, plus contact, privacy, and terms information. A sponsored word-search activity appears as an additional feature.