Core Time

The first thing companies discovered after letting people set their own hours is that nobody could be reached. One person starts at 7 in the morning and signs off at 4. Another arrives at 11 and works until 8 in the evening. They overlap for five hours, and once lunch and their separate meetings land inside that window, the time either of them can actually get the other's attention shrinks to about two hours.

Work then takes on a particular shape. A designer asks at 3 in the afternoon which of two screens a button should open, then logs off at 4. The engineer reads the message at 5 and writes an answer. The designer reads it the next morning and asks a follow-up. A thirty-second check has eaten two days. Whoever is in a hurry ends up phoning a colleague who has already finished for the day, and a policy built to give people flexibility turns into one where work can reach you at any hour.

Core time is the compromise that avoids choosing between those two outcomes. Instead of leaving the whole day open, a team carves a few hours out of the middle and declares them shared. The rest of the day belongs to each person, and anything that needs another human gets handled inside the shared block.

A team decides which hours of the day count as the shared block and agrees that during those hours everyone is reachable. Eleven in the morning to four in the afternoon is a common choice. Outside of it, people decide for themselves when to start and stop.

Three things have to be settled.

1. The length and position of the block. Four to six hours is typical. Cut it to three and two meetings fill it completely, leaving no room to ask anything. Stretch it to seven and there is barely an hour on each side, which is not much of a flexible schedule. Most teams place it across lunch, running from late morning into mid-afternoon.
2. What belongs inside it. Anything that needs several people at once — meetings, and questions that need an answer on the spot — moves into the block. That is synchronous communication: video calls and live back-and-forth, where both sides have to be present at the same moment.
3. What not to expect outside it. A question that arrives after the block closes can wait until the next morning, and everyone has to agree on that. Without this piece, the shared hours get added on top of the day rather than carved out of it, and personal time is still interrupted.

Settle one of the three and leave the others blank and the arrangement does not hold. Teams that announce the hours without saying what happens inside them end up with core time as a period when everyone simply happens to be online, while the recurring meeting stays where it always was, at 9:30 in the morning.

Solo, heads-down work is better pushed outside the block. Fill all five shared hours with the kind of work nobody can interrupt and there is no one to ask when a question comes up.

The most common setting is remote work and hybrid work. When nobody shares an office, or when office days differ from person to person, there is no way to see who is working right now. Core time replaces that glance with a rule: send a message at 2 in the afternoon and you can assume it is being read.

Teams spread across time zones have very little natural overlap to begin with. Seoul and Berlin are seven hours apart, so 4 in the afternoon in Seoul is 9 in the morning in Berlin. A team like that treats the two overlapping hours as core time and leaves everything else to asynchronous communication — written updates that move forward without both sides being present.

It also turns up in meeting hygiene rules. Adding one line — recurring meetings are scheduled inside core time — to the rules a team writes to keep meetings from multiplying makes anyone booking outside the block stop and reconsider first.

Job postings mention it too. "Flexible hours" tells a candidate nothing about where the limits are. Printing the actual hours lets someone who drops a child off in the morning work out whether their day fits.

"Let's take that to core time. Theo has already signed off."

There is no point raising it now, so it moves to when everyone is around.

"Our core time is 11 to 4, so that meeting slot is going to be hard."

The proposed time falls outside the block, so getting people there is unlikely.

"If you spend all of core time heads-down, there's nobody left to ask."

A request to move solo work outside the block and stay reachable during it.

Pagedeck runs core time from 11 to 4. Theo starts at 7:30 and finishes at 4:30; Noa comes in at 10 and stays until 7. Core time is effectively the only part of the day their schedules share, so any session where the two of them walk through a screen flow lands at 1 or 2 in the afternoon.

Mia checks the block before booking anything. If even one of six attendees would be outside core time, the meeting gets moved. And when a question posted at 9 in the morning is still unanswered by 10:30, nobody chases it, because the block has not started yet.

The most frequent mistake is reading core time as the full working day. It is the only span of hours the company names, so it sounds like the whole requirement. In fact it only marks the hours that have to overlap; how many hours a day someone works is set separately. If core time is 11 to 4 and the standard day is eight hours, three more have to sit somewhere on either side. Someone new who conflates the two leaves at 4 every day and hears a month later that their hours are short.

The opposite mistake also shows up: treating the block as the place where every meeting belongs. Since it is the only guaranteed overlap, that sounds like the obvious conclusion. But put four meetings into a five-hour block and, after lunch, one hour is all that is left of the day. Core time then becomes a container for meetings rather than hours for working alongside each other, and people escape to early mornings and late evenings to get their own work done. When more than half the block is meetings, the number of meetings is the thing to cut, not the size of the block.