If your operators are located all over the world, it might be confusing if messages show the wrong time zone. Make sure that each operator has the correct time zone set for their region. This can be set in the operator settings (click on the profile picture in the lower left
corner and then click on "My Profile").
However, if you are using a ticketing system such as Zendesk or Email Ticket, the organization time zone will always be displayed. You can check this under "Account > Organization" by clicking on the organization.