The first day of the week is different depending on which country you live in. Windows ought to use your regional settings to decide which is the first day of the week, or even how to display the date but it doesn’t. The regional settings only serve to set the date and check if a country follows day-light savings. It does little else with it as far as the date and time are concerned. The good thing about Windows 10 is that it lets users set a custom date format, and set the first day of the week to whatever day they like.
Set First Day Of The Week
In older versions of Windows, you had to go through the Windows Registry in order to set the first day of the week to anything other than the default. Thankfully, Windows 10 now lets you set the first day of the week from the Settings app.
Open the Settings app and go to the Time & Language group of settings. Select the Date & Time tab and scroll down to the Formats section. Here, click ‘Change date and time formats’.
Open the dropdown at the top and select which day you want to set as the first day of the week.
When you access the calendar from the system tray, the first day of the week will be whatever you selected in the Settings app.
Windows 7 & 8
As stated earlier, it’s harder to set the first day of the week in Windows 7 and 8. It isn’t impossible though you will need administrative rights to do it.
On Windows 7 and 8, open the registry and navigate to the following location;
HKEY_CURRENT_USERControl PanelInternational
Look for a key with the name, or something similar to FirstDayOfWeek. Its default value is 0 which represents Monday. Change it to 1 for Tuesday, 2 for Wednesday, etc.
You can set the first day of the week in Windows 10 through the registry as well but there isn’t any point doing it that way. The registry should only be used if there’s no other way to access a particular setting. It’s possible you might have to restart your system for the date and time to take effect on Windows 7 ad 8. This should not have any impact on other apps that use the Windows date and time setting. For example, apps like MS Excel should not be effected however, if you change the date format, you can expect the change to be reflected in apps like MS Excel and even MS Word.