Year First от Immanuel Washington

Every date on the page, in one format: 2024-01-05.

Year First rewrites dates as it finds them, largest unit first, in the
order that actually sorts. It reads the formats people write: January
5, 2024 and 5 Jan 2024 both become 2024-01-05; 23/07/2024 becomes
2024-07-23; 3/4/25 becomes 2025-04-03.

05/01/2024 is the hard one, because it means two different days
depending on who wrote it. Year First looks for other dates on the same
page that can only be read one way -- anything with a part above 12 --
and lets those decide. Failing that it uses the page's own language. Or
you can simply tell it: day first, month first, or work it out.

Timestamps marked up as time elements are read from their machine-
readable attribute, so "three hours ago" becomes a real date.

Some sites are better left as they are -- code review tools, log
viewers, anything where the original string is the point. The toolbar
popup has an off switch for the site you are on, separate from the
global one.

It is careful about what it does not touch. Code, preformatted text,
input fields and anything you are editing are left alone. Version
numbers like 1.2.3 survive, as do fractions, year ranges, and
impossible dates like 31/02/2024. A date already written as 2024-01-05
is left exactly as it is. Add data-no-year-first to skip any element
and everything inside it.

Dates that appear after the page loads get rewritten too.

No accounts, no network requests, no analytics, no data collection of
any kind. Your settings are stored by your browser and never leave it.
The source is public and readable -- nothing minified, nothing
bundled -- so you can check every word of this yourself.