A measure of distance which has an echo of ‘farflung’, though no direct connection.  It means one day’s walk or journey, or a day’s stage for a travelling caravan.  The OED describes it as ‘A Persian measure of distance—the Parasang of the ancients—about four miles’ (H. H. Wilson, Gloss. Ind. Terms.)

Which doesn’t sound bad for a day’s walk.

The word ‘journey’ itself, according to Stewart, comes from the French ‘journée’, as far as you can walk in a day.

Wish you a happy day’s walking.

Source: Rory Stewart, The Places in Between (London: Picador, 2014), p. 79 and 124