I often use the schedule message feature but often accidentally schedule messages at the wrong time because it has already passed. For example, at 4pm I want to schedule a message for 7pm, but accidentally choose 7am since it is the default; or at 9pm want to schedule a message for 8am tomorrow but choose 8am today since it is the default.

In both cases the message simply sends immediately. A warning for this would be helpful, or simply not allow selection of times that have already passed.