Its Adoption Upon Our Present Gregorian Calendar Would Only Require The Suppression Of The Usual Bissextile Once In Every 128 Years, And There Would Be No Necessity For Any Further Correction, As The Error Is So Insignificant That It Would Not Amount To A Day In 100,000 Years.
But At The End Of A Century The Order Is Interrupted In The Gregorian Calendar By The Secular Suppression Of The Leap Year; Hence The Cycle Can Only Be Employed During A Century.
This Long Period, However, May Be Reduced To Four Hundred Years; For Since The Dominical Letter Goes Back Five Places Every Four Years, Its Variation In Four Hundred Years, In The Julian Calendar, Was Five Hundred Places, Which Is Equivalent To Only Three Places (For Five Hundred Divided By Seven Leaves Three); But The Gregorian Calendar Suppresses Exactly Three Intercalations In Four Hundred Years, So That After Four Hundred Years The Dominical Letters Must Again Return In The Same Order.
Hence The Following Table Of Dominical Letters For Four Hundred Years Will Serve To Show The Dominical Letter Of Any Year In The Gregorian Calendar For Ever.
Perceiving That The Measure Was Likely To Confer A Great Eclat On His Pontificate, Undertook The Long Desired Reformation; And Having Found The Governments Of The Principal Catholic States Ready To Adopt His Views, He Issued A Brief In The Month Of March 1582, In Which He Abolished The Use Of The Ancient Calendar, And Substituted That Which Has Since Been Received In Almost All Christian Countries Under The Name Of The Gregorian Calendar Or New Style.