Technically, the breakfast entitlement is usually stated in terms of, for example, breakfast for up to two guests (staying in the room in the hotel) each day of the stay. If you're traveling alone, this doesn't mean that you can eat breakfast twice, in two different hotel restaurants, although many lounges have no problem if the same person comes and goes, for instance having coffee and juice early and coming back a bit later for the full breakfast, or eating lightly before a phone call/early meeting/work/exercise and then returning for more food.

I could envision an exception if someone had a Your24 with very strange hours that would involve leaving the following morning (for a one night stay in my example) before breakfast time, say arrive 5 am and leave 4 am the following day, where breakfast the morning of arrival would make sense, but you cannot normally take breakfast on two different days if you're paying for one night in the hotel even if the hotel charges the same rate for single and double rooms.