Named sets of hours
Work hours, personal hours, and work never lands in the wrong one.
One global "working hours" setting means personal errands land at 2pm on a Wednesday. Give each task a schedule and that's the only place it can go.
How to use it
Hours → Add a set → Name it → set Weekly hours per day. One of them is the Default, which is what a task gets when it doesn't say otherwise. Pick a task's schedule with When can this happen.
The honest version
Delete a schedule and its tasks survive. They end up with none, and get placed against the default.