That was a very logical question BP !!! Nothing to feel silly about at all !!!
If you want to make sure you understand, ask T the next time.
You can phrase it kinda like this if you want: (( Just what I would say - not telling you what to say ))

"T, you said you had a limited practice. I was wondering if that means you only do T work in certain hours? I wanted to know because if I need to call you, I would not want to call outside of those limited practice hours."