NAME

Date::Range - work with a range of dates

SYNOPSIS

  use Date::Range;

  my $range = Date::Range->new($date1, $date2);

  my $earliest = $range->start;
  my $latest   = $range->end;
  my $days     = $range->length;

  if ($range->includes($date3)) { ... }
  if ($range->includes($range2)) { ... }

  if ($range->overlaps($range2)) {
    my $range3 = $range->overlap($range2);
  }

  foreach my $date ($range->dates) { ... }

DESCRIPTION

Quite often, when dealing with dates, we don't just want to know information about one particular date, but about a range of dates. For example, we may wish to know whether a given date is in a particular range, or what the overlap is between one range and another. This module lets you ask such questions.

METHODS

new()

  my $range = Date::Range->new($date1, $date2);

A range object is instantiated with two dates, which do not need to be in chronological order (we'll sort all that out internally).

These dates must be instances of the correct object. See want_class() below.

want_class

The class of which we expect the date objects to be objects. By default this is Date::Simple, but this could be any other date class. See Time::Piece::Range for an example of a subclass that uses a different date class.

start / end / length

  my $earliest = $range->start;
  my $latest   = $range->end;
  my $days     = $range->length;

These methods allow you retrieve the start and end dates of the range, and the number of days in the range.

equals

  if ($range1->equals($range2)) { }

This tells you if two ranges are the same - i.e. start and end at the same dates.

includes

  if ($range->includes($date3)) { ... }
  if ($range->includes($range2)) { ... }

These methods tell you if a given range includes a given date, or a given range.

overlaps / overlap

  if ($range->overlaps($range2)) {
    my $range3 = $range->overlap($range2);
  }

These methods let you know whether one range overlaps another or not, and access this overlap range.

gap

        my $range3 = $range->gap($range2);

This returns a new range representing the gap between two other ranges.

abuts

        if ($range->abuts($range2)) { ... }

This tells you whether or not two ranges are contiguous - i.e. there is no gap between them, but they do not overlap.

dates

  foreach my $date ($range->dates) { ... }

This returns a list of each date in the range as a Date::Simple object.

AUTHOR

Tony Bowden, based heavily on Martin Fowler's "Analysis Patterns 2" discussion and code at http://www.martinfowler.com/ap2/range.html

BUGS and QUERIES

Please direct all correspondence regarding this module to: bug-Date-Range@rt.cpan.org

COPYRIGHT AND LICENSE

  Copyright (C) 2001-2006 Tony Bowden.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License; either version
  2 of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.