80

Year 80 (LXXX) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Domitianus (or, less frequently, year 833 Ab urbe condita). The denomination 80 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.

80 Plus (trademarked 80 PLUS) is a voluntary certification program intended to promote efficient energy use in computer power supply units (PSUs). Launched in 2004 by Ecos Consulting, it certifies products that have more than 80 nergy efficiency at 20%, 50 nd 100% of rated load, and a power factor of 0.9 or greater at 100% load. Such PSUs waste 20% or less electric energy as heat at the specified load levels, reducing electricity use and bills compared to less efficient PSUs.

Call blocking, also known as call block, call screening, or call rejection, allows a telephone subscriber to block incoming calls from specific telephone numbers. This feature may require an additional payment to the subscriber's telephone company or a third-party.

In calculus and other branches of mathematical analysis, limits involving an algebraic combination of functions in an independent variable may often be evaluated by replacing these functions by their limits; if the expression obtained after this substitution does not give enough information to determine the original limit, it is said to take on an indeterminate form. The term was originally introduced by Cauchy's student Moigno in the middle of the 19th century.

El año 80 (LXXIX) fue un año bisiesto comenzado en sábado del calendario juliano, en vigor en aquella fecha.

Het jaar 80 is het 80e jaar in de 1e eeuw volgens de christelijke jaartelling.

• Incendie du Champ de Mars et du Capitole à Rome. Épidémies.
• Titus inaugure l'amphithéâtre qui prendra le nom de Colisée à Rome. Des jeux s'y déroulent pendant cent jours.
• Une campagne militaire menée par Agricola dans le nord de la Bretagne atteint le Firth of Tay.
• Début du règne de Vima Taktu, roi kouchan (fin en 100).
• À Rome, Quintus Aurelius Pactumeius Fronto est le premier consul originaire d'Afrique (Cirta).
• Gamaliel II devient nassi du sanhédrin de Jamnia (mort vers 116).