Weekday as segment condition?

Is it possible to have weekday as a condition when defining a segment? A use case: getting visit counts by hour for Monday vs Saturday, or Monday-Friday vs weekend.

If it’s not there yet, how feasible is it to implement, will there be any technical/performance issue? (just trying to see if it worths development effort)

Would it be easier or more doable to implement the above use case as a widget instead? I think having it as a condition probably is more useful though.