Shell Programming and Scripting

31D 2H 1M

#!/usr/bin/ksh93
str="11:30:02-31.11.12"
# convert - and . to spaces 
str=${str/-/ }
str=${str//\./ }

# generic version
read time day month year << EOF
$str
EOF
# ksh93 can use also pipe reading
echo $str | read time day month year

year="20$year"
datestr="$year-$month-$day+$time" 
epoc1=$(printf "%(%#)T" "$datestr")
epoc2=$(printf "%(%#)T" now )

((d=60*60*24))
((h=60*60))

(( diff=epoc2-epoc1 ))
(( daycnt=diff/d ))
(( hcnt=(diff-daycnt*d)/h  ))
(( mcnt= (diff - daycnt*d - hcnt*h ) / 60 ))

printf "%dD %dH %dM\n" $daycnt $hcnt $mcnt

diff=$(( ($(date "+%s")-$(date -d "2012/12/30 16:15:59" "+%s")) ))

days=$(($diff/60/60/24))

test_log="2012/12/30 16:15:59"

diff=$(( ($(date "+%s")-$(date -d "${test_log}" "+%s")) ))
days=$(( $diff/86400 ))
hours=$(( ($diff-$days*86400)/3600 ))
minutes=$(( ($diff-$days*86400-$hours*3600)/60 ))

echo "${days}D ${hours}H ${minutes}M"

1D 18H 16M