[brucen]

If something runs weekly (e.g., every Saturday), it could be useful to verify the user has picked a Saturday. Not sure if the dropdown would grey out other days too, as that could be useful to be able to remove unavailable days.

[mattmanser]

You generally want the converse, the ability to block off Saturdays and Sundays.

[brucen]

Depends on the application obviously. A lot of social groups would likely be meeting once a week. It's just a simple example though of how the step function could be useful.

For your example, you would just need a step with some kind of range. So you could say step=7, range=5 to allow them to pick from the first 5 days of every 7 (or to get trick step=7 range=-2 to eliminate the last 2 days). I'd hazard a guess they thought about this kind of stuff, but realised it would be complicated pretty quickly.

[mattmanser]

Most applications are enterprise apps, the vast majority of apps in the world today are enterprise apps. That work Mon-Fri, so want to restrict date pickers to Mon-Fri.

And it doesn't have range, does it? So the infinitely more useful range hasn't been specified, but the almost useless step has.

https://html.spec.whatwg.org/multipage/forms.html#forms