It is the Mountain Standard Time Zone in which the US state of Colorado falls and if we take the data of all the time zones that exist in the United States of America falls, you can say that there are nine time zones that are in existence today and each of them are being given some code. They are called UTC 1, UTC 10, UTC 9, UTC 8, UTC 7, UTC 6, UTC 5, UTC 4 and UTC 10. You can also express them in a different way and can call them as Samoa Standard time, Hawaii-Aleutian Standard Time, Alaska Standard Time, Pacific Standard Time, Mountain Standard Time, Central Standard Time, Eastern Standard Time, Atlantis Standard Time and Chamorro Standard Time respectively.