Half an Hour Earlier Than You Think

Here is a pattern that shows up often enough to be worth naming. A couple picks an evening, decides on a length, and then chooses a start time by looking at the end of the working day and adding a comfortable margin. Session ends at six, so nine feels safe. The booking is at nine, and afterwards the report is that it was slightly too late.

The mistake is the direction of the calculation. Nine o'clock was chosen by counting forwards from the end of the programme. The thing that actually constrains a weekday evening is at the other end.

Counting backwards instead

Start with the alarm. Subtract the amount of sleep the working partner needs to be functional in a room full of people the next day, which on the third day of a conference is more than they think. Subtract fifteen minutes for a shower afterwards, and a little for the stretch of doing nothing that follows a session and should not be rushed. Subtract the length of the booking itself.

Do that arithmetic with a seven o'clock alarm and ninety minutes and you land somewhere near eight, not nine. Do it with a nine o'clock alarm and two hours and nine is fine.

Why the forwards calculation feels right

Because the visible problem in the early evening is the risk of being late. The programme might overrun. The walk back takes longer than expected. There might be a queue for the lift. All of those push in the same direction, towards a later start, and none of them is balanced by anything visible pushing the other way.

The morning is not visible at six in the evening. It becomes visible at half past eleven, which is too late to be useful.

The margin you actually need

Two hours between the end of the programme and the agreed hour is generally enough, and three is comfortable if the schedule has a habit of running long. That absorbs an overrun of twenty or thirty minutes without anybody having to write a message, and it leaves room for the shower and for the twenty minutes of quiet that a day of sessions requires.

What it does not need to include is dinner. A large meal an hour before a session is not a comfortable arrangement for the person who ate it. Something small at half past five, or something afterwards at half past nine, both work better than trying to fit a proper dinner into the gap.

Shape as a substitute for time

When the backwards arithmetic produces an hour that is earlier than the working partner can realistically be back, the answer is usually not to shorten the session. It is to change its shape.

One therapist between the two of you means the elapsed evening is the length of the booking: she works with one partner at a time while the other stays close. A therapist each means the two sessions run side by side, so ninety minutes of session occupies about forty-five minutes of evening. At EUR 720 an hour against EUR 360 that is a real difference in money, and on a night where the clock is the binding constraint it buys back exactly the thing that is short.

Writing an hour rather than a range

One further habit worth breaking. A message that offers a range, anywhere between eight and ten, feels accommodating and functions as indecision. Nothing is held, both sides keep the whole evening open, and the hour that was free when you wrote is gone by the time the range is resolved.

Write one hour. If it turns out to be wrong, changing the hour on the same date is a single message, and the arrival window of forty to sixty minutes from confirmation means a start time can be moved later on the day itself more easily than it can be moved earlier.

The exception

All of this applies to a weekday with a morning attached. On the last night of a trip, or on a Saturday added to the end of a trade week with a Sunday afternoon flight after it, the backwards calculation has nothing to push against. That is the night where two hours at ten is an entirely reasonable idea, and it is the only night of a working week where it is.