And there are different kinds of "hourly" workers. DD worked retail--at the beginning of the week, they told her when she was working. It might be ten hours one week, but 15 the next. I am nominally "hourly", but my job is "coded". I am in a position where I am expected to work 40 hours a week. If I don't work 40 hours, then I need to use vacation or sick leave hours to make up the difference.
My employer will send me to conferences. I usually do single-day, local ones. They pay my entrance fee, and I am paid as if I had worked at my branch that day. If I travel for one, they will pay hotel, per diem for meals, and airfare. (It's been a while since I've done that and I don't remember the details). I am also paid for an eight-hour day for each day of the conference.
Now, if I choose to go to a knitting conference, which is totally unrelated to my job, they don't pay for it, and I will need to use vacation to make up my 40 hours.