When working on a globally-distributed team, dealing with time zones might become an issue. Companies deal with this problem in different ways. Let's cover here what they do. If you have a different approach, please edit this page to share it.
By embracing asynchronous communication, dealing with time zones becomes a minor issue because people are not expected to work at the same time. Everyone do their own thing at their own time.
If your work is blocked by someone else's task, you send a message and work on something else while you wait for your previous task to be unblocked. This allows work to be really asynchronous:
If a company pulls too hard in the direction of one time zone (oftentimes the zone where most company executives live), it signals to the rest of the company that asynchronous workflows aren't taken seriously.
By working asynchronously, you never have to care on what time zone your colleagues are working.
Some companies have a policy of overlapping hours. Even though you can work from any time zone, you'd need to overlap some working hours among team members. Basecamp's Remote book, for example, recommends four hours of overlap. They think this avoids collaboration delays and it helps members to feel like a team.
InVision also uses this approach: they've set core hours to be between 10am-6pm (Eastern Standard Time). During those 8 hours, team members should aim to have, at least, a 4-hour overlap "to keep everyone on the same page and feeling connected with the rest of the company." To manage that overlap, you might need to work on weird hours for your time zone.