When you lie down and when you rise up

This is just a nodule of a thought really, not quite a post. But it is interesting to me that the command to recite the Shema "when you lie down and when you rise up" is presumed to refer to evening and morning recitations.

How odd it must be, for a night watchman or a third-shifter to help out with a morning minion and recite "who removes sleep from the eyes, slumber from the eyelids" before going to bed, or to recite Hashkiveinu at the start of his day.

The Shema itself, does not contain language linking it to the time of day it is recited, but the attendant blessings are.