It seems that some people like to use GMT hours and never forget to add "local time" when they talk about local time, which nobody normally does. Let's call those people "gmt freak".For those lost with UTC/GMT concepts: UTC/GNT conversion, you will better ground your conversation with your gmt-freak friends.

Since radio signals can cross multiple time zones and the international date line, some worldwide standard for time and date is needed. This standard is coordinated universal time, abbreviated UTC. This was formerly known as Greenwich mean time (GMT). Other terms used to refer to it include "Zulu time" (after the "Z" often used after UTC times), "universal time," and "world time."