Do not expect fireworks to mark the quatercentenary of John Milton's birth.
From the economist.com
Everyone is busy celebrating the quatercentenary of the King James bible.
From the guardian.co.uk
That sounds like an oxymoron, but it's actually a quatercentenary.
From the guardian.co.uk
In 2007 the quatercentenary of the premiere was celebrated by performances throughout the world.
From the en.wikipedia.org
The 1962 Glyndebourne Festival anticipated the quatercentenary with a lavish production using a new edition by Raymond Leppard.
From the en.wikipedia.org
Oxford University Press, which has published King James Bibles since the 17th century, will bring out a 1,520-page special quatercentenary edition.
From the economist.com
Santa Fe became the capital of the New Mexico province in 1610, making it the first state capital in the United States to celebrate its quatercentenary.
From the post-gazette.com
However, Blades's research proved that Caxton's first printing in England had in fact been in 1477, of a different book, so the quatercentenary celebrations were rescheduled accordingly.
From the en.wikipedia.org
More examples
Quatercentennial: the 400th anniversary (or the celebration of it)
An anniversary (from the Latin anniversarius, from the words for year and to turn, meaning (re)turning yearly; known in English since c. 1230) is a day that commemorates and/or celebrates a past event that occurred on the same day of the year as the initial event. ...