The live hour
The Hours Everybody Is Awake, Counted
The overlap between several working days is an arithmetic fact that takes five minutes to establish, and almost no schedule is built on it.
Who is working when, for the people on this page
Our engineering office, Auckland
Working 08:00 to 17:00
The client's technical department, Lisbon
Working 08:00 to 17:00 their time, which is 19:00 to 04:00 here
two parties · five days of the seven are working days for all of them · Mon, Tue, Wed, Thu, Fri
Five working days a week in common and not one working hour. Everything on that contract was going to be written down whether anybody planned for it or not.
A useful pilot starts with a baseline rather than a guess; teams can workday activity insights and compare capacity before and after changing a handoff or overlap window.
A useful independent source for this part of the workflow is European Union.
Four parties on one job, and the days on which a joint call is possible at all
Us, Hamburg
Working 08:00 to 17:00
The client's office, Dubai
Working 08:00 to 17:00 their time, which is 05:00 to 14:00 here
The fabrication shop, Taipei
Working 08:00 to 17:00 their time, which is 01:00 to 10:00 here
The forwarder, Chicago
Working 08:00 to 17:00 their time, which is 15:00 to 24:00 here
four parties · four days of the seven are working days for all of them · Mon, Tue, Wed, Thu
There are days on which all four of these are at work, and there is no hour on any of those days at which all four are at a desk. Every joint call on this job costs somebody their evening or their early morning, and the question is only whose. One team's own job.
Four parties, each working an ordinary eight-hour day, and no hour of the week in which all four are at their desks.
That is not an unusual case. It is what happens whenever a chain stretches across more than about eleven hours of longitude, which is most international work involving a buyer in Europe, a maker in Asia and a logistics party in the Americas.
The arithmetic
Convert everybody's working day into one reference zone and look for the intersection. It takes five minutes with a piece of paper and it is almost never done.
In the panel above, in Hamburg time: Dubai runs 05:00 to 14:00, Taipei runs 01:00 to 10:00, Chicago runs 15:00 to 24:00, and we run 08:00 to 17:00.
Dubai and Taipei overlap from 05:00 to 10:00. We overlap with that from 08:00 to 10:00. Chicago does not overlap with any of it.
What the result is used for
Three things, in descending order of how often they are actually done.
Knowing there is no hour. This is the one that changes behaviour most and is the easiest to establish. If no hour exists, the question "when shall we all get together" has no good answer and should stop being asked.
Finding the hours that do exist between pairs. Four parties produce six pairs, and most of them have a usable window even when the whole group does not. Most work gets done in pairs anyway.
Protecting the hour that exists. Where there is a narrow window — two hours in the example — it is the most valuable time on the schedule and should not be spent on a status meeting.
The pairs matter more than the group
| Pair | Overlap, ordinary working hours |
|---|---|
| Us and Dubai | 08:00–14:00 our time: six hours |
| Us and Taipei | 08:00–10:00 our time: two hours |
| Us and Chicago | 15:00–17:00 our time: two hours |
| Dubai and Taipei | 05:00–10:00 our time: five hours |
| Dubai and Chicago | None |
| Taipei and Chicago | None |
Two of the six pairs have no overlap at all, and those two pairs are the ones that will communicate entirely in writing whether anybody plans for it or not. Knowing which they are tells you where the written handovers have to be good, and where a phone call remains available as a fallback.
Doing it once per relationship
This is not a weekly exercise. The numbers are stable for as long as the parties are, and they change twice a year with daylight saving.
The useful output is two lines recorded alongside the counterparty's working week: the overlap in your own time, and whether it is in your morning or your afternoon. That is enough for anybody scheduling anything to get it right without repeating the arithmetic.
What the tools do and do not do
Scheduling tools handle the conversion correctly and are worth using for it.
What they do not know is whose working day is whose. A tool offering a slot at 07:00 for one party and 16:00 for another presents both as available, because both are inside a nominal working day somewhere. It has no view on the fact that one of those is before the school run and the other is the end of a long day.
The arithmetic is mechanical; the judgement about which hour to spend is not, and it is the judgement that determines whether the arrangement survives six months.
The honest conclusion for most chains
For a chain spread over more than about twelve hours, the right default is that there is no meeting.
The work gets coordinated in writing, in pairs, with each pair using whatever overlap it has for the conversations that genuinely need to be conversations. Attempting a single joint call forces three of the four parties to the margins of their day, and it produces a worse decision than three separate half-hours would.
Doing the arithmetic in the other direction
A second use for the same five minutes, and a more interesting one.
Instead of asking what hours are shared, ask what the offset would have to be for a particular arrangement to work, and whether that changes who you would choose.
A team that needs daily live contact with a fabricator has a real constraint: beyond about six hours of offset the daily call becomes an early morning or an evening for somebody, permanently. A team that needs contact twice a month has no such constraint and can buy from anywhere.
That distinction belongs at the start of a sourcing decision rather than after it, and it is rarely stated, because the question "how often will we actually need to talk to these people" is not one that comes up while anybody is comparing prices.