The answer
There is no accurate estimation because the Holy Scripture does not reveal this information explicitly. However, according Job 7:3, we could summate at least several months. The days and nights could have spread into years, but it is not corroborated explicitly:"So I have been allotted months of futility, and wearisome nights have been appointed to me" (Job 7:3).
Answered by His Eminence Metropolitan Youssef (opens in a new tab)