DateTime::Span(3pm)					User Contributed Perl Documentation				       DateTime::Span(3pm)

NAME

       DateTime::Span - Datetime spans

SYNOPSIS

	   use DateTime;
	   use DateTime::Span;

	   $date1 = DateTime->new( year => 2002, month => 3, day => 11 );
	   $date2 = DateTime->new( year => 2003, month => 4, day => 12 );
	   $set2 = DateTime::Span->from_datetimes( start => $date1, end => $date2 );
	   #  set2 = 2002-03-11 until 2003-04-12

	   $set = $set1->union( $set2 );	 # like "OR", "insert", "both"
	   $set = $set1->complement( $set2 );	 # like "delete", "remove"
	   $set = $set1->intersection( $set2 );  # like "AND", "while"
	   $set = $set1->complement;		 # like "NOT", "negate", "invert"

	   if ( $set1->intersects( $set2 ) ) { ...  # like "touches", "interferes"
	   if ( $set1->contains( $set2 ) ) { ...    # like "is-fully-inside"

	   # data extraction
	   $date = $set1->start;	   # first date of the span
	   $date = $set1->end;		   # last date of the span

DESCRIPTION

       "DateTime::Span" is a module for handling datetime spans, otherwise known as ranges or periods ("from X to Y, inclusive of all datetimes in
       between").

       This is different from a "DateTime::Set", which is made of individual datetime points as opposed to a range. There is also a module
       "DateTime::SpanSet" to handle sets of spans.

METHODS

       o   from_datetimes

	   Creates a new span based on a starting and ending datetime.

	   A 'closed' span includes its end-dates:

	      $span = DateTime::Span->from_datetimes( start => $dt1, end => $dt2 );

	   An 'open' span does not include its end-dates:

	      $span = DateTime::Span->from_datetimes( after => $dt1, before => $dt2 );

	   A 'semi-open' span includes one of its end-dates:

	      $span = DateTime::Span->from_datetimes( start => $dt1, before => $dt2 );
	      $span = DateTime::Span->from_datetimes( after => $dt1, end => $dt2 );

	   A span might have just a beginning date, or just an ending date.  These spans end, or start, in an imaginary 'forever' date:

	      $span = DateTime::Span->from_datetimes( start => $dt1 );
	      $span = DateTime::Span->from_datetimes( end => $dt2 );
	      $span = DateTime::Span->from_datetimes( after => $dt1 );
	      $span = DateTime::Span->from_datetimes( before => $dt2 );

	   You cannot give both a "start" and "after" argument, nor can you give both an "end" and "before" argument.  Either of these conditions
	   will cause the "from_datetimes()" method to die.

	   To summarize, a datetime passed as either "start" or "end" is included in the span.	A datetime passed as either "after" or "before" is
	   excluded from the span.

       o   from_datetime_and_duration

	   Creates a new span.

	      $span = DateTime::Span->from_datetime_and_duration(
		  start => $dt1, duration => $dt_dur1 );
	      $span = DateTime::Span->from_datetime_and_duration(
		  after => $dt1, hours => 12 );

	   The new "end of the set" is open by default.

       o   clone

	   This object method returns a replica of the given object.

       o   set_time_zone( $tz )

	   This method accepts either a time zone object or a string that can be passed as the "name" parameter to "DateTime::TimeZone->new()".
	   If the new time zone's offset is different from the old time zone, then the local time is adjusted accordingly.

	   If the old time zone was a floating time zone, then no adjustments to the local time are made, except to account for leap seconds.  If
	   the new time zone is floating, then the UTC time is adjusted in order to leave the local time untouched.

       o   duration

	   The total size of the set, as a "DateTime::Duration" object, or as a scalar containing infinity.

	   Also available as "size()".

       o   start

       o   end

	   First or last dates in the span.

	   It is possible that the return value from these methods may be a "DateTime::Infinite::Future" or a "DateTime::Infinite::Past"xs object.

	   If the set ends "before" a date $dt, it returns $dt. Note that in this case $dt is not a set element - but it is a set boundary.

       o   start_is_closed

       o   end_is_closed

	   Returns true if the first or last dates belong to the span ( begin <= x <= end ).

       o   start_is_open

       o   end_is_open

	   Returns true if the first or last dates are excluded from the span ( begin < x < end ).

       o   union

       o   intersection

       o   complement

	   Set operations may be performed not only with "DateTime::Span" objects, but also with "DateTime::Set" and "DateTime::SpanSet" objects.
	   These set operations always return a "DateTime::SpanSet" object.

	       $set = $span->union( $set2 );	     # like "OR", "insert", "both"
	       $set = $span->complement( $set2 );    # like "delete", "remove"
	       $set = $span->intersection( $set2 );  # like "AND", "while"
	       $set = $span->complement;	     # like "NOT", "negate", "invert"

       o   intersects

       o   contains

	   These set functions return a boolean value.

	       if ( $span->intersects( $set2 ) ) { ...	# like "touches", "interferes"
	       if ( $span->contains( $dt ) ) { ...    # like "is-fully-inside"

	   These methods can accept a "DateTime", "DateTime::Set", "DateTime::Span", or "DateTime::SpanSet" object as an argument.

SUPPORT

       Support is offered through the "datetime@perl.org" mailing list.

       Please report bugs using rt.cpan.org

AUTHOR

       Flavio Soibelmann Glock <fglock@gmail.com>

       The API was developed together with Dave Rolsky and the DateTime Community.

COPYRIGHT

       Copyright (c) 2003-2006 Flavio Soibelmann Glock. All rights reserved.  This program is free software; you can distribute it and/or modify
       it under the same terms as Perl itself.

       The full text of the license can be found in the LICENSE file included with this module.

SEE ALSO

       Set::Infinite

       For details on the Perl DateTime Suite project please see <http://datetime.perl.org>.

perl v5.12.4							    2011-08-22						       DateTime::Span(3pm)