;; Very well! Now we do the same for full-time, time-numoffset and time-offset:

(define partial-time
  (sequence* ((hour time-hour)
              (_ (is #\:))
              (minute time-minute)
              (_ (is #\:))
              (second time-second)
              (secfrac (maybe time-secfrac)))
             (result (list hour minute second secfrac))))

(define full-time
  (sequence partial-time time-offset))

; time-numoffset unchanged

; time-offset unchanged

;; And finally we can put together the new date-time

(define date-time
  (sequence* ((date full-date)
              (_ (is #\T))
              (time full-time))
             (result (list 'rfc3339-timestamp
                           date
                           time))))