RFC2822形式。

(defun insert-time ()
  (interactive)
  (insert (concat (substring (current-time-string) 0 20)
                  (nth 1 (current-time-zone))
                  (format-time-string " %Y"))))
(define-key global-map [(super t)] 'insert-time)

W3C-DTF。

(defun insert-w3cdtf ()
  (interactive)
   (insert (shell-command-to-string "w3cdtf")))
(define-key global-map [(super w)] 'insert-w3cdtf)

w3cdtfというコマンドを作っておく。

#!/usr/bin/perl
use DateTime::TimeZone;

$tz_name = `cat /etc/timezone`;
chomp $tz_name;

($sec, $min, $hour, $day, $mon, $year) = localtime(time());

$tz = DateTime::TimeZone->new(name => $tz_name);
$dt = DateTime->now();

printf("%04d-%02d-%02dT%02d:%02d:%02d+%02d:00\n",
       $year + 1900, $mon + 1, $day, $hour, $min, $sec,
       $tz->offset_for_datetime($dt) / 60 / 60);

とりあえずこんなとこ。

(@893)

＠ 考えたら: