Year 878 (DCCCLXXVIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.

Universal personal telecommunications (UPT) is a special segment of the international telephone number space which has been set aside for universal personal telephone numbers. This service has been allocated country code +878. UPT numbers differ significantly from personal numbers which are embedded as an area code within the national telephone numbering plan. For example, Area Code 070 within the UK plan.