@CENTURY — Returns the century number for a date or for a year.

Syntax:
%@CENTURY[date,infmt,flags]

datea date, or a four-digit year; defaults to today’s date
infmtthe input date format, used to interpret ambiguous dates
flags1 - append ordinal suffix, 2 - as a roman numeral

This function uses the convention that centuries begin with years ending in 01. The year 2000 was the last year of the 20th century, and 2001 began the 21st.