Two different things. There is the clock which tracks the time (simplifying here), and the timezone data that helps display the clock. Changing observances requires you to push an update to computers to tell them that humans have decided to change the rendering of the time but the time itself does not change.

You could do something like Google has done with the Leap Smear on a larger scale, but the better question is why does the clock change need to happen at all? There's really no reason for it.

It would be vastly easier for businesses which wish to let their employees out early enough to enjoy the sunlight to change their hours for a few months than for the entirety of society to change their sense of time.

Also, you'd be surprised how many clocks are not Internet-connected, as a lot of people still rely on clocks on their microwave, oven, car radio, etc. And in my case, I am absolutely reliant on one (or, often, like three) completely dumb alarm clocks, because they aren't subject to the whims of my phone doing dumb things like not ringing when it should.

> It would be vastly easier for businesses which wish to let their employees out early enough to enjoy the sunlight to change their hours for a few months than for the entirety of society to change their sense of time.

Actually it wouldn't, because businesses have their hours set based upon the entirety of society's sense of time.

This only really matters for customer-facing roles in specific-hours businesses. Anyone working in the background, in admin, or on project work likely doesn't need to be available in person 100% of the working hours.

Yes. The clock doesn't need to change. You can schedule your employees out early to enjoy sun if they like to do, regardless of what the clock says.

If you are scheduling a meeting, you will specify the time by the clock, but how to decide what time, can be decided by whatever else is applicable, such as when it is light or dark outside, or other considerations, and then know what time on the clock that time will be, to schedule.

Yes, many clock won't and shouldn't need to be Internet. Even so, you can also to use a sundial or pocketwatch, anyways. I also use "dumb" alarm clocks, actually.