How to format Date, so i get today is Tuesday

You can use DATE2DWY

e.g.

DATE2DWY(WORKDATE,1))

This will return an integer 1-7, Monday being 1.

You can then use this to switch in some text constants for the actual days of the week for display purposes.

Or you can format it to show the actual name:

FORMAT(WORKDATE,0,'<Weekday Text>');