main::(a.pl:49):	my $first_time_date_time=DateTime::Format::ISO8601->parse_datetime($first_time);
                                                                                                                                                               DB<2> p $first_time
2013-08-01T20:10:31
                                                                                                                                                               DB<3> n
main::(a.pl:50):	my $last_time_date_time=DateTime::Format::ISO8601->parse_datetime($last_time);
                                                                                                                                                               DB<3> p $last_time
2013-08-06T20:09:34
                                                                                                                                                               DB<4> n
main::(a.pl:51):	my $duration=$last_time_date_time->subtract_datetime($first_time_date_time);
                                                                                                                                                               DB<4> 
main::(a.pl:52):	my $days=$duration->days;
                                                                                                                                                               DB<4> p $duration
DateTime::Duration=HASH(0x1a2f268)
                                                                                                                                                               DB<5> p $duration->in_units('days')
4
                                                                                                                                                               DB<6> x $duration->deltas()
0  'months'
1  0
2  'days'
3  4
4  'minutes'
5  1439
6  'seconds'
7  3
8  'nanoseconds'
9  0
                                                                                                                                                               DB<7> $d=$last_time_date_time->delta_days($first_time_date_time)

                                                                                                                                                               DB<8> p $d
DateTime::Duration=HASH(0x1e1e2e8)
                                                                                                                                                               DB<9> p $d->in_units('days')
5