Return to Answer

DRAFT -- compatible with org-mode version 9.0.4?

COMPATIBLE WITH ORG-MODE 9.0.3

  (org-agenda-span 'day)
  (org-agenda-skip-function '(org-agenda-skip-deadline-if-not-today))
  (org-agenda-entry-types '(:deadline))

(add-to-list 'org-agenda-custom-commands
             '("b" agenda "Today's Deadlines"
               ((org-agenda-span 'day)
                (org-agenda-skip-function '(org-agenda-skip-deadline-if-not-today))
                (org-agenda-entry-types '(:deadline))
                (org-agenda-overriding-header "Today's Deadlines "))))

Emacs version 25.1 ships with org-mode version 8.2.10. Within said release, there is an undocumented dynamically scoped variable called org-agenda-only-exact-dates, which can be used to accomplish the goal of the original poster. Within the org-agenda-custom-commands, set (org-agenda-only-exact-dates t).

DRAFT -- compatible with org-mode version 9.0.4?

The function org-agenda-skip-deadline-if-not-today is designed to be used in conjunction with the org-agenda-skip-function and an agenda entry in the org-agenda-custom-commands that contains proposed entries such as:

  (org-agenda-span 'day)
  (org-agenda-skip-function '(org-agenda-skip-deadline-if-not-today))
  (org-agenda-entry-types '(:deadline))

(defun org-agenda-skip-deadline-if-not-today ()
"If this function returns nil, the current match should not be skipped.
Otherwise, the function must return a position from where the search
should be continued."
  (ignore-errors
    (let ((subtree-end (save-excursion (org-end-of-subtree t)))
          (deadline-day
            (time-to-days
              (org-time-string-to-time
                (org-entry-get nil "DEADLINE"))))
          (now (time-to-days (current-time))))
       (and deadline-day
            (not (= deadline-day now))
            subtree-end))))

COMPATIBLE WITH ORG-MODE 8.2.10

Emacs version 25.1 ships with org-mode version 8.2.10. Within said release, there is an undocumented dynamically scoped variable called org-agenda-only-exact-dates, which can be used to accomplish the goal of the original poster. Within the org-agenda-custom-commands, set (org-agenda-only-exact-dates t).