Answer:
1,000-year period
Step-by-step explanation:
It may have taken 500 years for most of the Psalms to be written but for them to be gathered, copied, and made into the Book Psalms took about a thousand years. The Old Testament has a timeline of a thousand years, and Psalms were written and added throughout that time. So, The book of Psalms was written over 1,000 years.