No, they switched to per-hour billing for their dedicated servers a while ago. I also tested this last week when I cancelled a dedicated server we had with them and they did indeed only charge for part of the month.
There's a difference in being charged a partial amount for the month vs an hourly amount for something you need for just 2 hours.
I have a dedicated machine with Hetzner, and AFAIK they charge me the full amount regardless of whether it's on or off. If I cancel on day 3 of the month, it makes sense to be charged for only those days' hours. However that's different to "turn it on for 6 hours" kind of hourly pricing.
