Please follow the steps as follows to update the weekly work pattern setup:
Go to the Core module.
Click Setup and click Calendar Setup.
Select the Calendar ID and click the 3-dotted button.
Click Work Pattern and select the Week Pattern ID.
Click the 3 dotted button.
Update the settings for the week, e.g. set off day to OFF, working day to FULL, and Save.
Go to Setup, Initialize New Year Setup and click Step 1.
Choose the year, move the Calendar ID to the right, and click Confirm.