Inconsistent datetime format on npmjs.com

[Ionaru]

While gathering information about some packages on https://www.npmjs.com/ I found out that the hover-tooltip labels for datetimes give me inconsistent formats in different places.

Some use dd/MM/YYYY, others use M/d/YYYY. Display of times are also inconsistant with 24hr/12hr mixed.

Output of navigator.languages

[
    "en-US",
    "en",
    "nl"
]

Output of Intl.DateTimeFormat().resolvedOptions()

{
    "locale": "en-GB",
    "calendar": "gregory",
    "numberingSystem": "latn",
    "timeZone": "Europe/Amsterdam",
    "year": "numeric",
    "month": "2-digit",
    "day": "2-digit"
}

[bradene0]

They might be using different date libraries, each handling things their own way. If it’s annoying, a browser extension like Tampermonkey might be able to fix it, but I'm not sure.

[leobalter]

@Ionaru can you help me specifying which parts are printing the different formats? I'm capturing some here but I wanna make sure I don't miss any. Thanks!

[Ionaru]

Header of a package: M/d/YYYY

Sidebar -> last publish: M/d/YYYY

Weekly downloads: ISO-8601 format 🎉

Version history: dd/MM/YYYY, correct format for my locale

Search results: no tooltip

Homepage when logged in, (Recently updated packages): no tooltip.

Profile page (https://www.npmjs.com/~ionaru) & My packages page (https://www.npmjs.com/settings/ionaru/packages): no tooltip.

That's all I could find.