ComputerImages
Musings

What Is UTC?

Often called Universal Time, for practical purposes it is the same as Greenwich Mean Time, only less Anglo-centric. It’s designed to synchronize time throughout the world, thus eliminating Fogg’s confusion.

Clock Face

When you set up a new computer you are asked to identify your time zone. The system then knows the difference between local and Universal Time. For example, Eastern Standard Time in Boston is five hours less than UTC (when it is noon in Boston it is 5:00 p.m. in London). Afterward whenever the computer time-stamps an entry, such as a calendar appointment or e-mail, it appends -0500. Universal Time does not change with the seasons, thus when we are on Daylight Savings Time, the offset from UTC is -0400. Remember the Southern hemisphere is not on daylight time now; It’s winter there.

The result is that if you use Outlook’s calendar to schedule a conference call among people in Boston, London, Rio and Tokyo, each person’s computer will show the proposed call times in the user’s local time.

Current Time is UTC.

This article originally appeared in our free semi-monthly newsletter. To receive future issues, please add your name to the subscription list.

Back to Main Musings Page

ComputerImages • 15 Court Sq., Boston, MA 02108 • (617) 720-6161 Visit us on FacebookVisit us on Twitter