Does the statement of Ibn Abbas (may Allah be pleased with him), "There were ten centuries between Adam and Noah," mean that there were a thousand years between the death of Adam and the birth of Noah? And does this apply to the remaining periods? Are these years based on contemporary calculations, or is "century" intended to mean a generation, and what is the measure of those calculations in contemporary terms?

It appears that the "centuries" (qurūn) mentioned between Noah and Adam refer to the period after Adam's death, as he lived for a thousand years (calculated by lunar months, twelve months). The reports regarding these timeframes are mostly derived from Israʼiliyyat (stories from Jewish traditions) which use solar reckoning, and there is disagreement regarding these periods. There is also a difference of opinion on the meaning of "qarn" (century/generation), whether it is one hundred years or less or more. Many have interpreted it as a generation of people who lived in the same era. There is no definitive textual evidence regarding this matter.