Universal Time Coordinated (UTC):
UTC is the time as maintained by the U.S. Naval Observatory. Because of variations in the Earth’s rotation, UTC is sometimes adjusted by an integer second. The accumulation of these adjustments compared to GPS time, which runs continuously, has resulted in an offset between GPS time and UTC. After accounting for leap seconds and using adjustments contained in the navigation message, GPS time can be related to UTC within 20 nanoseconds or better. (http://www.magellangps.com/en/about/aboutgps/glossary.asp)
And why is this important? Well, I can’t seem to figure out how to change the date and time stamp on this blog. As such, the time that I actually post will be different from what is written on the page because of different time zones. Hope this isn’t too confusing!
