Halliday &
Matthiessen (2004: 419):
Nominal conjunctions include in case, in the event that, to the extent that, and the + various nouns of time and manner, eg the day, the moment, the way. These last have evolved from prepositional phrases with the enhancing clause embedded in them, eg on the day when we arrived; but they now function to introduce hypotactic clauses just like other conjunctions, eg their daughter was born the day we arrived, the way they’re working now the job’ll be finished in a week. Note that they no longer have the nominal group potential for modification; thus while we can say on the beautiful day when we arrived, it would be odd (or impossible) to say their daughter was born the beautiful day we arrived.