How many years between psalms and gospel of john?

The Psalms is a collection of "Praises" that were written by 7 identifiable authors and a number of unidentifiable authors, God being the overall Arthur. They span a time period of about 900 years from Moses who wrote Psalm 90 to the late 6th or early 5th century B.C.

John it is supposed wrote his Gospel in A.D. 80-90. The time period between the last Psalms and John' Gospel would be about 600 years.