
  Anno Lucis
  The
  Masonic Calendar
  
  The Masonic calendar
  traditionally dated from 4004 BCE; the creation of the universe, Anno Mundi,
  as computed by Bishop Ussher in 1650-54 and stated in the margins of older
  printings of the Authorized King James Bible. This was replaced in
  Masonic documents by the year of light, Anno Lucis, which dates from
  4000 BCE. There is no Masonic significance to either date, other than a desire
  by early Masonic writers to create as ancient a lineage for Freemasonry as
  their imaginations would allow.
  
"Bro. John J. Bond, in his Handy
  Book of Rules and Tables, to our mind gives a clue to this difference,
  which we never remember seeing noted elsewhere, as applicable to the subject.
  'The birth of our Lord took place in the 28th year of the reign of Augustus;
  and Dionysius, by reckoning from 727 A.U.C., the year in which the Emperor
  took the name of Augustus, made the 28th year fall to 754 A.U.C., four years
  short of the date observed by the early Christians, who reckoning their years
  of the Emperor from the date of the battle of Actium (723 A.U.C.). to
  commemorate which the era of the Roman Emperors was founded, made the 28th
  year of Augustus fall to 750 A.U.C. for the birth of our Lord, or "Anno
  Christi.'"
  Kenning's Masonic Cyclopaedia and Handbook of Masonic Archaeology, History
  and Biography. A.F.A. Woodford, ed. George Kenning, London: 1878. p. 650.
  

  James Ussher (1581-1656), an
  Irish theologian and scholar, at one time had possibly the largest collection
  of books in Western Europe.  A tireless collector, he eventually donated
  the collection to Trinity College, Dublin, which his uncle Henry Ussher
  (c.1550-1631) helped found. During his lifetime he was widely known as a
  defender of learning, of the value of books secular and sacred, and a
  proponent of maintaining an independent identity for Irish Protestant faith.
  He was appointed Archbishop of Armagh in 1625.
  What he is best remembered for
  is his chronology of creation.  Using the Book of Genesis, and
  other histories, he determined that the universe was created in the year 4004
  BCE, on October 23rd, beginning at sunset of the 22nd. Starting in 1701, this
  chronology was inserted in the margins of many editions of the King James
  Authorized Version of the Bible. Dr. John Lightfoot later refined the
  computation to 9:00 a.m.