You can customize your Calendar settings in Windows 10, such as working days and hours, or color options.
Open Calendar and choose Settings .
Note: On a phone or tablet, choose More at the bottom of the page to open Settings .
Choose Calendar Settings, and then select the options you want under First Day of Week, Working Hours, Week Numbers, and Color Options.
Note: Calendar for Windows 10 uses the date settings you specify in Windows. To change these settings, go to the Time & Language settings in Windows.