Coordinated Universal Time (UTC) is used as the official world reference for time. Coordinated Universal Time replaced the use of Greenwich Mean Time (GMT) in 1972, however, the same principles used in GMT have been carried over into UTC.
UTC uses a 24-hour system of time notation. To convert UTC to local time, you have to add or subtract hours from it, as shown in table below.

PS.: Summer Time/Daylight Savings Time are not considered.

• UTC/GMT +1: most part of Europe and West of Africa.
• UTC/GMT -5: most part of USA and northwest of South America.
• UTC/GMT -3: Brazil and south-east of South America.
• UTC/GMT +3: European Russia, Arabian Peninsula and east of Africa.