Which time zone applies

The system time zone is a fallback. Anything that carries its own zone wins, which is why two people can read one booking differently and both be right.

Updated 15 Aug 2026

The system time zone decides the time for everything that has not been given one of its own.

The part that surprises people

A room can run on a different time from the system default — and you will not find a time zone anywhere on the room to explain it.

It comes from the room’s business hour. A business hour carries a time zone alongside the days and opening times it defines, and every room it is applied to follows that zone. A room with no business hour, or one whose business hour has no zone, falls back to the system time zone.

Three cards in a row, each a large icon above its name. Room carries a red icon and a badge reading never has one; an arrow marked so it asks leads to Business hour, amber, may have one; an arrow marked if it is empty leads to System time zone, green and highlighted as the answer, always has one. — How a room's time zone is decided. The first level that has one wins.

Each business hour carries its own time zone.

People are the same in spirit: each person keeps their own display preference, which is why two colleagues can look at one booking, read different clock times, and both be correct.

Why it works that way

An organisation in more than one city has no single right answer. If one global setting won, every site outside headquarters would read the wrong time, and the people most affected — the ones booking those rooms — would be the least able to fix it.

Keeping the zone on the business hour rather than on each room is what makes opening times mean anything. 09:00–18:00 is not a fact on its own; it is only a fact somewhere. The same object that decides when a room can be booked has to decide where in time those hours are counted, or a Tokyo room would open at nine in London.

It also means one edit moves a whole site. Change the business hour and every room on it moves together, instead of a hundred rooms drifting apart one at a time.

What it does not control

A building’s time zone. A building shows one, taken from the location on its map, but that is a label for the site rather than the rule a booking follows. The booking follows the room’s business hour.

Whether times read as 1:00 PM or 13:00. That is a display preference each person sets for themselves, not a system setting, and it changes nothing about when anything is scheduled.

The clock on the device in front of you. Offision does not reset a phone or a PC. When a device’s own zone differs from the one in use, Offision points it out and offers to reload rather than quietly overriding it — so a laptop still on holiday time shows a prompt, not a silently wrong calendar.

Open System interface