API, feed and embed
Everything on What's On This Date is available as JSON, as an Atom feed and as a small embeddable widget. No key, no sign-up. Keep the source attribution with anything you reuse.
JSON endpoints
All paths are relative to this app’s address. Responses are JSON, cached for a few minutes, and safe to call from a browser on the same origin.
| Endpoint | What it returns | Try it |
|---|---|---|
/api/today | Today's date, entry count and the standout entry. | open |
/api/dates/:slug | Every entry for one calendar day, grouped and dated. | open |
/api/birthday/:slug | The same day framed as a birthday report, with births first. | open |
/api/events/:slug | One entry in full: summary, encyclopedia panels, sources and siblings. | open |
/api/people/:slug | One person: life dates, biography, related people. | open |
/api/people/weekly | The seven people featured this week. | open |
/api/calendar | All twelve months with per-day entry counts. | open |
/api/calendar/:month | One month, day by day, with the top entries for each day. | open |
/api/years | Every year with entries, grouped by century and decade. | open |
/api/years/:year | Everything recorded for one year, grouped by month. | open |
/api/anniversaries | Round-number anniversaries falling in the current year. | open |
/api/search?q= | Keyword search across titles and summaries. | open |
Atom feed
/feed.xml carries today’s entries and refreshes every day. Point any reader at it, or use it to drive a daily post.
Embed today in history
Drop this into any page. It is a plain iframe with no tracking and no cookies.
<iframe src="https://whatsonthisdate.com/app/embed/today" title="Today in history" width="100%" height="420" style="border:1px solid #ddd;border-radius:8px" loading="lazy"></iframe>The widget shows today’s standout entry and the next few, each linking back to the full record. See the widget on its own.
Machine-readable index
/llms.txt lists the site’s URL patterns, the JSON endpoints and the licence in one plain-text file for language models and crawlers. The /sitemap.xml index points to per-section sitemaps with last-modified dates.
Licence
Text derived from Wikipedia is CC BY-SA 4.0 — attribute and share alike. Wikidata facts are CC0. Images carry their own licences, listed with each image. See sources and licensing for the detail.
Developer questions
Is there an API key or a rate limit?
No key. Responses are cached and cheap to serve, but please keep requests to a sensible rate and cache what you fetch rather than polling.
Can I use this data in my app?
Yes, within the source licences: Wikipedia-derived text is CC BY-SA 4.0 and must be attributed and shared alike, Wikidata facts are CC0. Keep the attribution with the data.
Does the feed update every day?
Yes. The Atom feed always describes today's date, so a reader picks up a fresh set of entries each morning.
Can I embed the widget on my own site?
Yes. The iframe is small, has no tracking, and shows today's entries with a link back. It follows your page width.