"I'll Get You"

I listened to the second disc of On Air - Live at the BBC, Volume 2 this morning and noticed a small thing in "I'll Get You" (which is also in the studio version).  The first line of the second verse is "I think about you night and day," and "night and day" is an example of a rhetorical device called a merism in which two points of a range are named as a way to refer to the entirety.  While the description here is "night and day," the sense is really "all the time."