Of course you make the reservation for the night of the 25th given that check in time is usually from around 3pm on the day of the reservation and not shortly after midnight the night before. It would be a spectacular Your 24 if you could shoehorn an extra night into the stay by checking in so early and insisting on your 4pm Platinum check out time on the day of departure
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I face this issue every time I go to Bangkok and the hotel emails me before and asks what time I will be arriving. I invariably arrive about 12.30-1am. However, it's much more straightforward to tell them that I will arrive at 11.30pm both by email and when I check in on the app the day before. It avoids any confusion. I'm done with the conversation about which midnight/12am I mean for a reservation that starts on a Friday. Do I mean middle of the night on Thursday? Or Friday? What is obvious to you may not be obvious to someone communicating in a second language. Now I just say 11.30pm and copy them my flight details.