(princ month stream)
(princ #\- stream)
(when (< day 10) (princ #\0 stream))
- (princ month stream)
- (princ #\space stream)
+ (princ day stream)
+ (princ #\T stream) ;strict ISO says T here isn't optional.
(when (< hour 10) (princ #\0 stream))
(princ hour stream)
(princ #\: stream)