If Angle end is greater than Angle start, the tool travels counter-clockwise.
Angle start = 0
Angle end = 120
Tool moves counter-clockwise
If Angle end is less than Angle start, the tool moves clockwise.
Angle end = 0
Angle start = 120
Tool travels clockwise
To machine an area counter-clockwise starting at 350 and ending at 10 you need to think about the values you enter. If you enter an Angle start of 350 and an Angle end of 10 then the tool travels clockwise and machines the opposite of what you want. So you must enter an Angle start of 350 and an Angle end of 370 to get the result you want.