Year 351 (CCCLI) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Magnentius and Gaiso (or, less frequently, year 1104 Ab urbe condita). The denomination 351 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Portugal changed to a closed telephone numbering plan in 1999. Previously, the trunk prefix was '0', but this was dropped. The area code, prefixed by the digit '2', was incorporated into the subscriber's number, so that a nine-digit number was used for all calls.