bash-2.05b$ perl -MTime::localtime -e 'print "0" .  localtime->mon() + 1, "\n"'
1
bash-2.05b$ perl -MTime::localtime -e 'print +("0" . localtime->mon()) + 1, "\n"'
1
bash-2.05b$ perl -MTime::localtime -e 'print "0" . (localtime->mon() + 1), "\n"'
01