Checking if a given date falls between 2 other specific dates

[stacy]

I'd like to be able to check if a given date is between 2 other specific dates (these 2 will always be within the 60 days mof the date when the script is run). I have seen postings that indicate using the Date::Calc module - actually the Date-Calc module which I read somewhere is the compiled binary version of the module so I installed it via PPM. However in browsing this module, I found that it contains C components so requires the C compiler which I do not have on my Windows 2000 system. Or perhaps there is some easier way to determine if the given date falls between the 2 other specified dates? Btw, I am new to Perl. I also went to http://www.apache.org/dyn/closer.cgi/perl/win32-bin/ but got "The page cannot be found" for each link I tried there. I'd appreciate any help that can be offered.Thanks. Stacy

[chargrill]

Date::Manip is one module that's pure perl, and by the author's documentation, attempts to be the swiss army knife of date modules.

But if that doesn't help, a search on CPAN might. Last time I needed something to do with dates (earlier today, in fact), I did a search, read through some of the various module's documentation, and picked the one that made the most sense.

[johngg]

If your date strings are consistent and simple to break down then you would be able to use the Time::Local module which is a standard part of Perl. The localtime() function turns date values for second, minute etc. into the number of seconds elapsed since the epoch for your particular o/s. Like this

my $epochSecs =
   localtime($secs, $mins, $hours, $mday, $mon, $year);

Note that $mon is 0 for January to 11 for December.

Once you have converted your three dates to epoch seconds you can do a simple numeric comparison.

If, however, your date strings are complex and inconsistent then using a module as chargrill suggests would probably be less painful.

Cheers,

JohnGG

Update: tag cock-up corrected

[blazar]

To put it briefly: if you install a binary module (i.e. containing C code to be compiled) with PPM, then you'll get a binary version (i.e. complete of compiled binaries suitable for your architecture & current perl). In any case, you should not "browse this module" - unless you're curious about its implementation, that is. You installed it, then you can read its documentation with perldoc and use it straight out of the box: did you try doing so?

[monsterzero]

You did not specify what format your dates are in. But no matter, DateTime can handle most date/time functions.

use strict;
use warnings;
use DateTime;
use DateTime::Span;
use Datetime::Format::ISO8601;

my $iso8601 = DateTime::Format::ISO8601->new;

while (<DATA>) {
    my ( $first, $last ) = split('\|');
    chomp $last;
    my $dt_set = DateTime::Span->from_datetimes(
        start  => $iso8601->parse_datetime($first),
        before => $iso8601->parse_datetime($last),
    );
    if ( $dt_set->contains( DateTime->now() ) ) {
        print "Within date range\n";
    }
    else {
        print "Not within date range\n";
    }
}

__DATA__
1998-02-14|1998-03-01
2006-04-10|2006-06-01

I hope this helps.

[TedPride]

Convert the dates to a numerical, fixed-width, greatest significance first format. For instance, if you have Feb 12, 06, you could translate that to 060112, then compare numerically:

use strict;
use warnings;

my $date1 = dateconvert('Jan 11, 04');
my $date2 = dateconvert('Jan 30, 04');
my $date3 = dateconvert('Feb 10, 04');

print "$date1 <= $date2 <= $date3 ? ";
print $date1 <= $date2 && $date2 <= $date3 ? "Yes" : "No";

BEGIN {
    my @mon = qw/Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec/;
    my %mon; $mon{$mon[$_]} = $_ for 0..$#mon;
    sub dateconvert {
        my $date = $_[0];
        my ($mon, $day, $year) = $date =~ m/(\w+) (\d+), (\d+)/;
        $mon = $mon{$mon};
        return sprintf("%02d%02d%02d", $year, $mon, $day);
    }
}

This is easily modified for different formats by changing a couple lines in the function.