Very recently, while using a Mac, I noticed that macOS (Catalina) displays day of the week on the menu bar in addition to the clock. Windows 10, on the other hand, displays date and time on the taskbar. With default settings, Windows 10 does not display day of the week on the taskbar.
If you often get confused about day of the week, you can configure the Windows 10 to display the day of the week besides the date and clock.
NOTE: The Settings > Time & Language > Region > Change data formats page allows you to choose between many date formats. However, it does not offer day of the week, at least in the current version 1909. Day of the week shows up only when it is selected in the classic Control Panel. You can use the Settings app to choose other types of the date and time formats, though.
Display day of the week on the Windows 10 taskbar
Complete the given below directions to make Windows 10 taskbar display the day of the week in addition to date and time.
Step 1: Open the Settings app. Navigate to Time & Language > Region.
Step 2: In the Related settings section, click on the Additional date, time, & regional settings link. Clicking the link will open the classic Clock and Region window.
Step 3: Here, in the Region section, click Change date, time, or number formats link.
Step 4: Under the Formats tab, click the Additional settings button to open the Customize Format dialog.
Step 5: Switch to the Date tab. In the Date formats section, next to the Short date field, add ddd (for short day of the week format) or dddd (if you want to see long day of the week format) at the beginning followed by hyphen (refer to the picture below). For example, adding ddd displays Thu only, and adding dddd displays Thursday.
Once done, click on the Apply button.
If the day of the week is not showing up, restart your computer once, after saving your work.
Bonus tip: You can configure Windows 10 to completely hide the clock from the taskbar. To do that, go to Settings > Personalization > Taskbar, click Turn system icons on or off link and then turn off the toggle button next to the clock.
How to display date on macOS menu bar guide might also interest you.