UTC+06:00 is an identifier for a time offset from UTC of +06:00. This time is used in:
UTC−06:00 is a time offset that subtracts 6 hours from Coordinated Universal Time (UTC). In North America, it is observed in the Central Time Zone during standard time, and in the Mountain Time Zone during the other 8 months (see Daylight saving time). Several Latin American countries and a few other places use it year round.
CST is standard time in the 6th time zone west of Greenwich, reckoned at the 90th meridian; used in North America in some parts of Canada, Mexico and the United States.