Parse ISO8601 (Zulu) string

read-datetime.el

(defun gongo:read-datetime ()
  (unless (re-search-forward "\\([0-9]\\{4\\}\\)-\\(0[1-9]\\|1[0-2]\\)-\\(0[1-9]\\|[1-2][0-9]\\|3[0-1]\\)T\\([0-1][0-9]\\|2[0-4]\\):\\([0-5][0-9]\\):\\([0-5][0-9]\\)Z" nil t)
    (message "error"))
  (let ((seconds (string-to-number (match-string-no-properties 6)))
        (minutes (string-to-number (match-string-no-properties 5)))
        (hour    (string-to-number (match-string-no-properties 4)))
        (day     (string-to-number (match-string-no-properties 3)))
        (month   (string-to-number (match-string-no-properties 2)))
        (year    (string-to-number (match-string-no-properties 1))))
    (list seconds minutes hour day month year)))

(let (datetime)
  (setq datetime (with-temp-buffer
                   (insert "1979-05-27T07:32:00Z")
                   (goto-char (point-min))
                   (gongo:read-datetime)))
  (format-time-string "%Y-%m-%d [%H:%M:%S]" (apply 'encode-time datetime)))
;; => "1979-05-27 [07:32:00]"