Centurial stones are numerous, having been put up at all parts of the Wall to record the building of such and such parts by various centurions and their companies.
"Northumberland Yesterday and To-day"
Jean F. Terry
This is corrected by the Gregorian, by making three consecutive Centurial years common years, thus suppressing three days in 400 years.
"Our Calendar"
George Nichols Packer
It is not interrupted, however, at the end of every century, for the leap-year is not suppressed in every fourth Centurial year; consequently the cycle will then be continued for two hundred years.
"Our Calendar"
George Nichols Packer