The English lyrics to "Book of Days" are not a translation of the Irish lyrics. Instead, they are an alternate version produced for the movie Far and Away. The Irish lyrics and their translation are as follows.
Book of Days
Ó oíche go hoíche, mo thuras, From night to night, my journey,
An bealach fada romham. The long pilgrimage before me.
Ó lá go lá, mo thuras, From day to day, my journey,
na scéalta na mbeidh a choích. The stories that will be forever.
(Translation by Dave Allum)