On what basis can a piece of literature can be called modern? What are the basic elements of modernity in literature?

The accumulations of the refined heritages and cultures of
the different races , the progressions of their thoughtless ,the reformations of habits
are certainly the modern elements of
life.

Literature reflects life ,and it is life enhancing
.The fashion of an age , its cultures , and its acceptance of values need to nourish the
inner life of a society .The time gap , I think , matters little .Which is best for us
 ,- we can't tell .But we can feel what makes life better .These are  the wholesomeness
of life , restrictions to certain perversions , controls of the impulses , values ,
discriminations on moral issues ,
etc.

Chaucer's Canterbury Tales , Shakespeare's Measure for
Measure , Merchant of Venice , Hardy's The Return of the Native , Austen's Pride
and Prejudice , Dickens,- Hard Times ,-are some of the literary works in progression
that have their  claim as modern literature .Every one of them has permanent values .If
we compare them with 20th -century literature as , Joyce's Ulysses , and Osborne's,-Look
Back In Anger , we find -the same wine in a new bottle .They have change only in degree
of representation , not in kind .