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.
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.
Another circumstance to which it is often necessary to pay attention in the comparison of dates, is the alteration of style which took place on the adoption of the Gregorian Calendar (see Calendar).
The Gregorian Calendar Was Introduced Into Spain, Portugal And Part Of Italy The Same Day As At Rome.
It Has Already Been Mentioned That The Error Of The Julian Year Was Corrected In The Gregorian Calendar By The Suppression Of Three Intercalations In 400 Years.
When The Epact Of The Year Is Known, The Days On Which The New Moons Occur Throughout The Whole Year Are Shown By Table Iv., Which Is Called The Gregorian Calendar Of Epacts.
On the railways and in post offices the Gregorian calendar is employed; elsewhere the Julian remains in use.
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.
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.
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.