(when (string-match date-re date-string re-start)
(setq year (string-to-number (match-string 1 date-string))
month (string-to-number (match-string 2 date-string))
(when (string-match date-re date-string re-start)
(setq year (string-to-number (match-string 1 date-string))
month (string-to-number (match-string 2 date-string))