No, the datepicker controls are based on someone else's code and have limited functionality. You can't even set Monday as the first day of the week.
As a workaround you can put a label beside the DateTime Input component and with an expression binding give the user a warning.
if(
(getDayOfWeek({../DateTimeInput.props.value}) = 1)
||
(getDayOfWeek({../DateTimeInput.props.value}) = 7),
"Please select weekday!",
""
)
With a similar expression you could disable the "Save" button or whatever.