I'm also curious about the "no way to do this" response. It worked fine until recently, as others have said.
I stopped using Reminders in Cortana for this exact same reason two or three years ago. Out of the blue, you couldn't scroll through the hours and minutes to set the time. Seriously annoying.
Some of us who work on computers all day have RSIs and do as little clicking as possible. Making us click and drag - in extremely narrow and disappearing scroll bars, no less - is just mean, Microsoft!