I want to book a room at the Incheon Airport Transit Hotel in South Korea. They have a rate for a "12 hour use" room. I'm booking it on hotels.com but there's nothing that lets me specify exactly which 12 hours I want. I just have a check-in date and check-out date (which I specified to be April 15th and April 16th, respectively).
Here's an example of what I see on Hotels.com
How does this work exactly? Does this assume I want to stay the night? Do the 12 hours begin when I check in?