Shell Programming and Scripting

 timediff=`awk -v "time=$stTime" -v "date=$(date +%H:%M:%S)" '
  function abs(x) {return x<0 ? -x : x}
  BEGIN {
    split(time, ary, /[:,]/); t_sec = 3600*ary[1] + 60*ary[2] + ary[3]
    split(date, ary, /:/);    d_sec = 3600*ary[1] + 60*ary[2] + ary[3]
    # output difference in minutes
    print abs(t_sec - d_sec)/60
  }

#!/usr/bin/perl

use Time::Local;

my @TA1=split(/\//, shift);
my @TA2=split(/\//, shift);

for($N=6; $N>=0; $N-=2)
{
        @TA1[2+($N/2)]=substr(@TA1[2], $N, 2);
        @TA2[2+($N/2)]=substr(@TA2[2], $N, 2);
}

@TA1[7]=timelocal(@TA1[5], @TA1[4], @TA1[3], @TA1[1], @TA1[0], @TA1[2]);
@TA2[7]=timelocal(@TA2[5], @TA2[4], @TA2[3], @TA2[1], @TA2[0], @TA2[2]);

print @TA1[7] - @TA2[7], "\n";

$ ./tdiff.pl 09/17/13101536 09/16/13101536
86400

$