What time zone are you calling?
Before you call and wake people up in the middle of the night, it's a good idea to just check what time it is in the country you are dialing.
How does a 24 hour clock work?
Outside of North America many countries use the 24 hour clock. The military also uses it.
|US Time||24 Hour|
What does "GMT" mean?
Greenwich Mean Time (GMT) is a term originally referring to mean solar time at the Royal Observatory, Greenwich in London.
In October 1884 and following fierce discussions, particularly between the French and British delegations, the International Meridian Conference adopted in Washington the Greenwich meridian as the prime meridian for the measure of Longitude.
So time zones around the world are coordinated according to Greenwich Mean time or more recently, UTC - which is effectively the same thing as Greenwich Mean Winter Time (No daylight Savings).