Day's journey
A Day's journey in pre-modern literature, including the Bible, ancient geographers and ethnographers such as Herodotus, is a measurement of distance.
In the Bible, it is not as precisely defined as other Biblical measurements of distance; the distance has been estimated from 32 to 40 kilometers.
In translation by J.B. Bury
We set out with the barbarians, and arrived at Sardica, which is thirteen days for a fast traveller from Constantinople. From Constantinople-Istanbul to Sofia is 550–720 km distance at a pace between 42 and 55 km /day.
