In Exodus 10, how long did darkness cover Egypt during the ninth plague?

In Exodus 10, darkness covered Egypt for three days during the ninth plague.

The darkness is described as so thick that people could not see one another or leave their places for three days. The Israelites, however, are said to have had light where they lived. This contrast is part of the narrative’s repeated distinction between Egypt and the Israelite community.

The ninth plague comes immediately before the final plague and after the locust plague. Pharaoh again attempts to negotiate, offering to let the people go while restricting their livestock, but Moses insists that the animals must also accompany them for worship. Pharaoh refuses, and the confrontation continues.

This three-day period should not be confused with the three days of travel mentioned elsewhere in Exodus, or with the seven-day duration of the Feast of Unleavened Bread. It is specifically the stated length of the darkness plague.