Re: This day

 I usually hear of appointments being "pushed back" (made later) or
"pushed up" (made earlier), which is an odd pairing; I'd expect either
of them and its usual antonym (foreward or down).

I acknowledge that "next /weekday/" is ambiguous.  But "top" and
"bottom of the hour" are quite intuitive to me, relating as they do to
the minute hand's position at the top or bottom of the clock,
respectively.

etymonline.com agrees that the "to" in "to-day" is the locative, not a
demonstrative.