Read Genesis 15:2-6. what seems to have been the time of the day, and why does that matter?

Read Genesis 15:2-6, in which Abraham's faith is counted as righteousness.  How might trying to count the stars in the sky have helped Abraham to trust in God's promise, and how is this a profound example of what faith requires? (Hint: what seems to have been the time of the day, and why does that matter?)