Date difference using perl

Shell Programming and Scripting
1

Hi All,

I am using the below code to get the days difference between 2 dates

ddate="05/31/2018"
bdate="06/10/2018"
diff=$(perl -e 'use Time::Local;
my ($month1,$day1,$year1)=split /\W+/, $ENV{'ddate'};
my ($month2,$day2,$year2)=split /\W+/, $ENV{'bdate'};
my $time1 = timelocal($sec1,$min1,$hour1,$day1,$month1,$year1);
my $time2 = timelocal($sec2,$min2,$hour2,$day2,$month2,$year2);
$time = ($time2 - $time1)/86400;
print $time;')
echo $diff

When i try to run the script I get the below error

Day '31' out of range 1..30 at -e line 4

I understand that this is due to the array placement in perl, but i am not sure how to get the script working. Please help on this.

2

The month range in Time::Local names is from 0 to 11 not from 1 to 12.

See: Time::Local - Day '31' out of range 1..30

Subtract 1 from the month number and it will work. Otherwise you hit the error here that "5" is not May but June, which has 30 Days and causes an error.

3

Hi,

thanks for the reply.

If i use "-1" with month, then i get the below error.

diff=$(perl -e 'use Time::Local;
my ($month1,$day1,$year1)=split /\W+/, $ENV{'ddate'};
my ($month2,$day2,$year2)=split /\W+/, $ENV{'bdate'};
my $time1 = timelocal($sec1,$min1,$hour1,$day1,$month1-1,$year1);
my $time2 = timelocal($sec2,$min2,$hour2,$day2,$month2-1,$year2);
$time = ($time2 - $time1)/86400;
print $time;')

Month '-1' out of range 0..11 at -e line 4

How do i change the month here ?

4

-1 is not a valid value vor month either.

You may use "debug prints" in your code to verify the values of the variables.

5

No. What stomp means is perl uses a zero based month: i.e., January is zero ... so June is 5. perl is based on the standard C library, and timelocal is being supplied with what amounts to a struct tm in the C language.
From the man page:

      struct tm {
               int tm_sec;    /* Seconds (0-60) */
               int tm_min;    /* Minutes (0-59) */
               int tm_hour;   /* Hours (0-23) */
               int tm_mday;   /* Day of the month (1-31) */
               int tm_mon;    /* Month (0-11) */
               int tm_year;   /* Year - 1900 */
               int tm_wday;   /* Day of the week (0-6, Sunday = 0) */
               int tm_yday;   /* Day in the year (0-365, 1 Jan = 0) */
               int tm_isdst;  /* Daylight saving time */
           };

This is the same thing, almost, as your ($sec, $min, $hour,.....)

Try: Time::Local - perldoc.perl.org

6

Works OK for me here with the new -1 version:

$ export ddate="05/31/2018"
$ export bdate="06/10/2018"
$ diff=$(perl -e 'use Time::Local;
 my ($month1,$day1,$year1)=split /\W+/, $ENV{'ddate'};
 my ($month2,$day2,$year2)=split /\W+/, $ENV{'bdate'};
 my $time1 = timelocal($sec1,$min1,$hour1,$day1,$month1-1,$year1);
 my $time2 = timelocal($sec2,$min2,$hour2,$day2,$month2-1,$year2);
 $time = ($time2 - $time1)/86400;
 print $time;')
$ echo $diff
10