By default, the date and time displayed at the bottom right of your Windows 10 desktop is something like this:

How about adding the day of the week, like this?

Interested? Here is how you can quickly do it.
Go to Settings > Time & Language > Region and click Additional date, time & regional settings link.

It opens the Clock and Region applet in Control Panel. Click Region to open the Region dialog box. Then click Additional settings… button at the near of the bottom.

Now switch to Date tab, and here we can change the Short date format to add the day of the week to the taskbar.
ddd M/d/yyyy brings you the format shown in the screeshoot above.

And dddd M/d/yyyy brings you this:

The change takes effect right away. You don’t need to restart the computer or even File Explorer. If you don’t see it, it’s probably you’ve set to use small taskbar buttons in Taskbar settings.

I wouldn’t touch that setting. It affects the entire system and will cause trouble formatting and parsing short dates in all apps the rely on these regional settings (which is every good app).
Yes, the taskbar date format change is system wide and not individual fitting Win10 simplistic coding attitude.