Weekend colors and custom date cell background colors

Please add customization options for the monthly calendar view:

1. Allow different colors for specific weekdays, especially Sunday in red and Saturday in blue.

2. Allow users to fill an entire date cell with a custom background color, similar to DesktopCal, so important dates can be highlighted at a glance.
   These would make the monthly view much easier to scan, especially for users who keep the calendar open on their desktop all day.