It happens to almost everyone and it is remarkably consistent. An evening winds down, tiredness arrives somewhere around eleven, and then at about one in the morning it lifts. The eyes open properly. The idea of going to bed becomes uninteresting. Something that felt impossible an hour ago now feels like a good plan.
A lot of bookings are made in that fifteen minutes. They are not bad bookings, but they are made on a misreading, and the misreading is worth correcting because it affects the only decision that matters at that point, which is how long.
What is actually happening
The body does not run tiredness on a single sliding scale. Sleep pressure builds through the day, but the clock that decides when you feel alert runs on its own cycle, and it produces a rise in the late evening and small hours that has nothing to do with how rested you are. What lifts at one in the morning is alertness, not recovery. Sleep pressure is still there underneath it, undiminished, waiting.
Which means the second wind is a loan rather than an income. It will be called in, usually abruptly, and usually somewhere between forty and ninety minutes after it arrived.
What that does to a booking
Two things, and they point in opposite directions, which is why this is worth thinking about rather than just knowing.
First, do not book short on the strength of it. The reflex at one is to say an hour, because an hour feels proportionate to the amount of night that seems to be left. But an hour arranged at one starts at about two, and by half past two the loan is being called in. An hour that ends exactly as your body gives up is the least satisfying version of this. Ninety minutes or two hours, which end after that collapse rather than at it, are better bookings and the arithmetic is not close.
Second, do not book something that asks anything of you. The second wind is alertness without stamina. It will hold up a conversation for ten minutes and then not. Formats that let you do nothing at all are the right ones here: slow, warm, oil-based, unhurried. Warm oil work is the obvious one and there is a reason it is the most requested format after midnight.
The variant that is not a second wind
There is a different one o'clock alertness and it needs the opposite advice. If you arrived in the city yesterday from several time zones east or west, what you are feeling at one is not a second wind at all. It is the middle of your own afternoon, and it is not going to be called in at half past two. It will hold for hours.
That guest can book anything, including long. Two or three hours at one in the morning is a coherent booking for a body on another continent's clock, and an overnight is not an extravagance but the format that actually fits, since an inverted clock has nowhere useful to be at four. The guide for inverted clocks goes through this properly.
How to tell which one you are
Two questions. Did you sleep last night at your usual time in your usual place? And has the alertness arrived once, cleanly, after tiredness, or has it been there all evening without ever really lifting? A single clean rise after tiredness is the second wind. Steady wakefulness that has not gone away since eight in the evening is a clock problem, and it is a different night.
What it means for the message
Write the honest version. If you have been awake since six and this is a second wind, say the length you are choosing and let the thread confirm it, rather than ordering the minimum and regretting it at three. The fee does the same arithmetic either way: EUR 180 for an hour, EUR 270 for ninety minutes, EUR 360 for two hours, with no night rate and nothing added for the hour on the clock.
And book with a shower in mind afterwards rather than a plan. A second wind night ends well when the session finishes after the collapse rather than at it, followed by hot water, curtains closed properly, and no alarm. The note on sleeping afterwards covers the last part of that.