Hastings' Dictionary of the Bible (1898)
JOUR'NEY. The Orientals travel in the morning early or in the evening, often into the night, resting during the heat of the day. A day's journey was from 10 to 20 miles, Deut 1:2; a sabbath day's journey was 2000 paces, or three-quarters of a mile. But it is at least probable that the phrase in the Bible, "a day's journey," does not mean any definite length, but simply as far as was travelled on that particular day.