Here is the reset-clock example with the addition of a command button that will set the number of seconds to zero.
(defun reset-clock (stream)
(multiple-value-bind (second minute hour day month)
(decode-universal-time (get-universal-time))
(declare (ignore second))
(format stream "Enter the time~%")
(restart-case
(progn
(clim:accepting-values
(stream)
(setq month
(clim:accept 'integer :stream stream
:default month :prompt "Month"))
(terpri stream)
(setq day
(clim:accept 'integer :stream stream
:default day :prompt "Day"))
(terpri stream)
(setq hour
(clim:accept 'integer :stream stream
:default hour :prompt "Hour"))
(terpri stream)
(setq minute
(clim:accept 'integer :stream stream
:default minute :prompt "Minute")))
(terpri stream)
;; Print the current time to the terminal.
(accept-values-command-button
(stream) "Print-Clock"
(format t
"~%Current values: Month: ~D, Day: ~D, Time: ~D:~2,'0D."
month day hour minute))))
(abort () (format t "~&Time not set")))))