Alternatively, since you're getting the values from a database, see if you can get it to return the values in the format yyyy-mm-dd; then a simple string comparison will do. Or - heck - get it in nnnnnnnnn format, a number representing seconds since the epoch. Then a simple numeric comparison will do!

If the date you want to compare is in the same format as that you are pulling from the database, you might be able to perform a SELECT statement on it and let the database tell you which date is younger (or older).

This method requires a connection to a database, and might not be the fastest way, but if you are designing for portability, would require less packages be installed than going whole hog and installing Date::Manip.

You could also just compare the dates manually. I.e:

($d,$m,$y) = split /-/, $date;
$dv1 = $d+31*$m+365*$y;
($d,$m,$y) = split /-/, $date_from_db;
$dv2 = $d+31*$m+365*$y;

if ($dv1 < $dv2) {
    something;
    ...
    ...
    done;
}
[download]

Cheers,
KM

Originally posted as a Categorized Answer.

Originally posted as a Categorized Answer.

Rather than getting the current date using `date`, why not use POSIX::strftime to get it in YYYY-MM-DD format. You can then use standard string comparison operators on the two dates.

use POSIX 'strftime';
 
my $now = strftime('%Y-%m-%d', localtime);
[download]

Date::Manip is probably overkill for this task (in fact it's probably overkill for most tasks.)

Originally posted as a Categorized Answer.

sub abs_day
{
        # this subroutine accepts a month, day, and two-digit year in 
        # mm/dd/yy numerical form, e.g., 3/23/04.
        # it then calculates the "absolute day", 
        # i.e., the number of days
        # since day 0, which is the turn of the 21st century. 
        # so, 1/10/2000 is absolute day 10;       
        # 1/10/2001 is absolute day 376
        # (because year 2000 was a leap year).

        # the routine deals with leap years by
        # multiplying years by 365.25, and then rounding down.

        my $month = shift(@_);
        my $day = shift(@_);
        my $year = shift(@_);

if ($debug)
{
  print "i'm in abs_day and month is $month,", 
        " day is $day, year is $year\n";
}
        my $abs_day;
        undef($abs_day);

        # so each year has 365.25 days
        # years are of the form 00, 01, 02, etc.
        $abs_day = $year * 365.25;
        # add .75 to account for fact that year 00 is a leap year
        $abs_day = $abs_day + .75;

if ($debug)
{
  print "abs_day is $abs_day after adding .75 to yr*365\n";
}


        if ($month == 1) #jan
        {
                $abs_day =  $abs_day + 0;
        }
        if ($month == 2) #feb
        {
                $abs_day = $abs_day + 31;
        }
# starting in march, we add .25 to number of days 
# to account for leap year
        if ($month == 3) #mar
        {
                $abs_day = $abs_day + 59.25;
        }

        if ($month == 4) #apr
        {
                $abs_day = $abs_day + 90.25;
        }
        if ($month == 5) #may
        {
                $abs_day = $abs_day + 120.25;
        }
        if ($month == 6) #jun
        {
                $abs_day = $abs_day + 151.25;
        }
        if ($month == 7) #jul
        {
                $abs_day = $abs_day + 181.25;
        }
        if ($month == 8) #aug
        {
                $abs_day = $abs_day + 212.25;
        }
        if ($month == 9) #sep
        {
        }
        if ($month == 11) #nov
        {
                $abs_day = $abs_day + 304.25;
        }
        if ($month == 12) #dec
        {
                $abs_day = $abs_day + 334.25;
        }

        $abs_day = $abs_day + $day;
if ($debug)
{
  print "now that we have added year, month, and",
        " day, abs_day is $abs_day\n";
}

        $abs_day = sprintf "%d", $abs_day;
if ($debug)
{
  print "now that we have converted from float to integer,",
        " abs_day is $abs_day\n";
}

        return $abs_day;
}
[download]

$dv1 = $d+31*$m+365*$y;
$dv2 = $d+31*$m+365*$y;
[download]

$dv1 = $yyyymmdd
$dv2 = $yyyymmdd
[download]

Originally posted as a Categorized Answer.