To improve Calculate Number of Days Command - unix

Question

Would like to generate report, which calculate the number of days, the material is in the warehouse.
The number of days is the difference between date ($3 field) the material comes in and
against (01 OCT 2014) manual feed date.
Input.csv
Des11,Material,DateIN,Des22,Des33,MRP,Des44,Des55,Des66,Location,Des77,Des88
aa,xxx,19-AUG-14.08:08:01,cc,dd,x20,ee,ff,gg,XX128,hh,jj
aa,xxx,19-AUG-14.08:08:01,cc,dd,x20,ee,ff,gg,XX128,hh,jj
aa,yyy,13-JUN-14.09:06:08,cc,dd,x20,ee,ff,gg,XX128,hh,jj
aa,yyy,13-JUN-14.09:06:08,cc,dd,x20,ee,ff,gg,XX128,hh,jj
aa,yyy,05-FEB-14.09:02:09,cc,dd,x20,ee,ff,gg,YY250,hh,jj
aa,yyy,05-FEB-14.09:02:09,cc,dd,y35,ee,ff,gg,YY250,hh,jj
aa,zzz,05-FEB-14.09:02:09,cc,dd,y35,ee,ff,gg,YY250,hh,jj
aa,zzz,11-JUN-13.05:06:17,cc,dd,y35,ee,ff,gg,YY250,hh,jj
aa,zzz,11-JUN-13.05:06:17,cc,dd,y35,ee,ff,gg,YY250,hh,jj
aa,zzz,11-JUN-13.05:06:17,cc,dd,y35,ee,ff,gg,YY250,hh,jj
Currently i am using below command to popualte Ageing - No of days at $13 field ( thanks to gboffi)
awk -F, 'NR>0 {date=$3;
gsub("[-.]"," ",date);
printf $0 ",";system("date --date=\"" date "\" +%s")}
' Input.csv | awk -F, -v OFS=, -v now=`date --date="01 OCT 2014 " +%s` '
NR>0 {$13=now-$13; $13=$13/24/3600;print $0}' >Op_Step11.csv
while using the above command in Cygwin (windows), it is taking 50 minutes for 1 Lac (1,00,000) rows of sample input.
Since my actual input file contains 25 million rows of lines , it seems that the script will take couple of days ,
Looking for your suggestions to improve the command and advice !!!
Expected Output:
Des11,Material,DateIN,Des22,Des33,MRP,Des44,Des55,Des66,Location,Des77,Des88,Ageing-NoOfDays
aa,xxx,19-AUG-14.08:08:01,cc,dd,x20,ee,ff,gg,XX128,hh,jj,42.6611
aa,xxx,19-AUG-14.08:08:01,cc,dd,x20,ee,ff,gg,XX128,hh,jj,42.6611
aa,yyy,13-JUN-14.09:06:08,cc,dd,x20,ee,ff,gg,XX128,hh,jj,109.621
aa,yyy,13-JUN-14.09:06:08,cc,dd,x20,ee,ff,gg,XX128,hh,jj,109.621
aa,yyy,05-FEB-14.09:02:09,cc,dd,x20,ee,ff,gg,YY250,hh,jj,237.624
aa,yyy,05-FEB-14.09:02:09,cc,dd,y35,ee,ff,gg,YY250,hh,jj,237.624
aa,zzz,05-FEB-14.09:02:09,cc,dd,y35,ee,ff,gg,YY250,hh,jj,237.624
aa,zzz,11-JUN-13.05:06:17,cc,dd,y35,ee,ff,gg,YY250,hh,jj,476.787
aa,zzz,11-JUN-13.05:06:17,cc,dd,y35,ee,ff,gg,YY250,hh,jj,476.787
aa,zzz,11-JUN-13.05:06:17,cc,dd,y35,ee,ff,gg,YY250,hh,jj,476.787
I don't have the access to change the input format and dont have perl & python access.
Update#3:
BEGIN{ FS=OFS=","}
{
t1=$3
t2="01-OCT-14.00:00:00"
print $0,(cvttime(t2) - cvttime(t1))/24/3600
}
function cvttime(t, a) {
split(t,a,"[-.:]")
match("JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC",a[2])
a[2] = sprintf("%02d",(RSTART+2)/3)
return( mktime("20"a[3]" "a[2]" "a[1]" "a[4]" "a[5]" "a[6]) )
}

Answer 1

Since you are on cygwin you are using GNU awk which has it's own built-in time functions and so you do not need to be trying to use the shell date command. Just tweak this old command I had lying around to suit your input and output format:
function cvttime(t, a) {
split(t,a,"[/:]")
match("JanFebMarAprMayJunJulAugSepOctNovDec",a[2])
a[2] = sprintf("%02d",(RSTART+2)/3)
return( mktime(a[3]" "a[2]" "a[1]" "a[4]" "a[5]" "a[6]) )
}
BEGIN{
t1="01/Dec/2005:00:04:42"
t2="01/Dec/2005:17:14:12"
print cvttime(t2) - cvttime(t1)
}
It uses GNU awk for time functions, see http://www.gnu.org/software/gawk/manual/gawk.html#Time-Functions

Answer 2

Here is an example in Perl:
use feature qw(say);
use strict;
use warnings;
use Text::CSV;
use Time::Piece;
my $csv = Text::CSV->new;
my $te = Time::Piece->strptime('01-OCT-14', '%d-%b-%y');
my $fn = 'Input.csv';
open (my $fh, '<', $fn) or die "Could not open file '$fn': $!\n";
chomp(my $head = <$fh>);
say "$head,Ageing-NoOfDays";
while (my $line = <$fh>) {
chomp $line;
if ($csv->parse($line)) {
my $t = ($csv->fields())[2];
my $tp = Time::Piece->strptime($t, '%d-%b-%y.%T');
my $s = $te - $tp;
say "$line," . $s->days;
} else {
warn "Line could not be parsed: $line\n";
}
}
close($fh);