Within the settings, there is a separate section for adjusting the overview options. This section includes two settings: Hide menu and First day of the Week.

Hide menu
When this option is enabled, the overview menu is hidden by default when opening a dashboard or overview. You can then open the overview menu by clicking on the green arrow in the top left of the overview.

First day of the Week
Here you can choose what you consider the first day of the week and select your choice from the drop-down menu.