Check out on the same day as the hotel reservation.

Generally speaking, it is an international practice to calculate by day. Unless you open a small room or negotiate with them when you check in, others have the right to calculate by the day.

To tell you some common sense, most hotels check in at 2 pm and check out at noon the next day 12. Of course, there will be some differences in check-in and check-out time according to the specific situation, but almost all of them are from afternoon to noon the next day. If you stayed the night before, you should check out when it is time to check out. For example, if you didn't check out at 12 and checked out at 2 pm, people have reason to give you an extra half-day room rate.

Similarly, if you come in the early morning, say five o'clock in the morning, stay until noon 12, even if it's half a day, it's only in the afternoon. If you stay for a long time, such as a few days, you will come early on the first day. For example, if you say eight o'clock, you may not count, but you will definitely count if you don't say hello in advance, so the time you say will normally count as one day.