Variable: display-time-hook
display-time-hook is a customizable variable defined in time.el.gz.
Value
nil
Documentation
List of functions to be called when the time is updated on the mode line.
Source Code
;; Defined in /usr/src/emacs/lisp/time.el.gz
;;;###autoload(put 'display-time-string 'risky-local-variable t)
(defcustom display-time-hook nil
"List of functions to be called when the time is updated on the mode line."
:type 'hook)