A day's journey in the East is from 16 to 20 miles (Numbers 11:31).
A Sabbath-day's journey is 2,000 paces or yards from the city walls (Acts 1:12). According to Jewish tradition, it was the distance one might travel without violating the law of Exodus 16:29. (See SABBATH .)
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Journey'". "Easton's Bible Dictionary". <http://classic.studylight.org/dic/ebd/view.cgi?number=T2119>. 1897.