;; This file: http://user.it.uu.se/~embe8573/conf/emacs-init/time-my.el

(require 'linux-shell)

(defun time-between-times (year1 month1 day1
                           year2 month2 day2)
  (let*((seconds-then  (float-time (encode-time 0 0 0 day1 month1 year1)))
        (seconds-now   (float-time (encode-time 0 0 0 day2 month2 year2)))
        (seconds-diff  (- seconds-now seconds-then)) )
    (format-seconds "%Y, %D" seconds-diff)))

(defun get-time-since (year month day)
  (interactive "nyear: \nnmonth: \nnday: ")
  (message "%s" (format-seconds
                 "%Y, %D"
                 (float-time
                  (time-since (encode-time 0 0 0 day month year)) ))))

;; test:
;;   (time-between-times 1996 5 11 2002 9 30)
;;   (time-between-times 2008 10 17 2015 5 6)
;;   (time-between-times 2010 4 15 2015 3 16)
;;   (insert "\n;; " (get-time-since 2013 12 1))
;; 2 years, 92 days

(defun message-shell-command-output (command)
  (interactive "s$ ")
  (with-temp-buffer
    (shell-command command 1)
    (message (buffer-substring (point-min) (1- (point-max)))) ))

;; `show-time-and-date' relies on the zsh function long-date in
(defun show-time-and-date (&optional insert)
  (interactive "P")
  (let ((date-script "long-date"))
    (if insert (insert-shell-command date-script)
      (message-shell-command-output date-script) )))

(defalias 'd 'show-time-and-date)

(provide 'time-my)