- NAME
- VERSION
- SYNOPSIS
- DESCRIPTION
- METHODS
- DateTime::Duration->new( ... )
- $dur->clone
- $dur->in_units( ... )
- $dur->is_positive, $dur->is_zero, $dur->is_negative
- $dur->is_wrap_mode, $dur->is_limit_mode, $dur->is_preserve_mode
- $dur->end_of_month_mode
- $dur->calendar_duration
- $dur->clock_duration
- $dur->inverse( ... )
- $dur->add_duration($duration_object), $dur->
subtract_duration($duration_object)
- $dur->add( ... ), $dur->subtract( ... )
- $dur->
multiply($number)
- DateTime::Duration->compare( $duration1, $duration2, $base_datetime )
- $dur->delta_months, $dur->delta_days, $dur->delta_minutes, $dur->delta_seconds, $dur->delta_nanoseconds
- $dur->deltas
- $dur->years, $dur->months, $dur->weeks, $dur->days, $dur->hours, $dur->minutes, $dur->seconds, $dur->nanoseconds
- Overloading
- SEE ALSO
- SUPPORT
- SOURCE
- AUTHOR
- COPYRIGHT AND LICENSE
DateTime::Duration - Duration objects for date math
version 1.55
use DateTime::Duration;
$dur = DateTime::Duration->new(
years => 3,
months => 5,
weeks => 1,
days => 1,
hours => 6,
minutes => 15,
seconds => 45,
nanoseconds => 12000,
end_of_month => 'limit',
);
my ( $days, $hours, $seconds )
= $dur->in_units( 'days', 'hours', 'seconds' );
# Human-readable accessors, always positive, but consider using
# DateTime::Format::Duration instead
$dur->years;
$dur->months;
$dur->weeks;
$dur->days;
$dur->hours;
$dur->minutes;
$dur->seconds;
$dur->nanoseconds;
$dur->is_wrap_mode;
$dur->is_limit_mode;
$dur->is_preserve_mode;
print $dur->end_of_month_mode;
# Multiply all values by -1
my $opposite = $dur->inverse;
my $bigger = $dur1 + $dur2;
my $smaller = $dur1 - $dur2; # the result could be negative
my $bigger = $dur1 * 3;
my $base_dt = DateTime->new( year => 2000 );
my @sorted
= sort { DateTime::Duration->compare( $a, $b, $base_dt ) } @durations;
if ( $dur->is_positive ) {...}
if ( $dur->is_zero ) {...}
if ( $dur->is_negative ) {...}
This is a simple class for representing duration objects. These objects are
used whenever you do date math with DateTime.
See the How DateTime Math Works section
of the DateTime documentation for more details. The short course: One cannot
in general convert between seconds, minutes, days, and months, so this class
will never do so. Instead, create the duration with the desired units to begin
with, for example by calling the appropriate subtraction/delta method on a
DateTime object.
Like DateTime itself, DateTime::Duration returns the object from mutator
methods in order to make method chaining possible.
DateTime::Duration has the following methods:
This class method accepts the following parameters:
- years
An integer containing the number of years in the duration. This is optional.
- months
An integer containing the number of months in the duration. This is optional.
- weeks
An integer containing the number of weeks in the duration. This is optional.
- days
An integer containing the number of days in the duration. This is optional.
- hours
An integer containing the number of hours in the duration. This is optional.
- minutes
An integer containing the number of minutes in the duration. This is optional.
- seconds
An integer containing the number of seconds in the duration. This is optional.
- nanoseconds
An integer containing the number of nanoseconds in the duration. This is
optional.
- end_of_month
This must be either "wrap", "limit", or "preserve". This parameter
specifies how date math that crosses the end of a month is handled.
In "wrap" mode, adding months or years that result in days beyond the end of
the new month will roll over into the following month. For instance, adding one
year to Feb 29 will result in Mar 1.
If you specify "limit", the end of the month is never crossed. Thus, adding
one year to Feb 29, 2000 will result in Feb 28, 2001. If you were to then add
three more years this will result in Feb 28, 2004.
If you specify "preserve", the same calculation is done as for "limit"
except that if the original date is at the end of the month the new date will
also be. For instance, adding one month to Feb 29, 2000 will result in Mar 31,
2000.
For positive durations, this parameter defaults to "wrap". For negative
durations, the default is "preserve". This should match how most people
``intuitively'' expect datetime math to work.
All of the duration units can be positive or negative. However, if any of the
numbers are negative, the entire duration is negative.
All of the numbers must be integers.
Internally, years as just treated as 12 months. Similarly, weeks are treated as
7 days, and hours are converted to minutes. Seconds and nanoseconds are both
treated separately.
Returns a new object with the same properties as the object on which this
method was called.
Returns the length of the duration in the units (any of those that can be
passed to DateTime::Duration->new) given as arguments. All lengths are
integral, but may be negative. Smaller units are computed from what remains
after taking away the larger units given, so for example:
my $dur = DateTime::Duration->new( years => 1, months => 15 );
$dur->in_units('years'); # 2
$dur->in_units('months'); # 27
$dur->in_units( 'years', 'months' ); # (2, 3)
$dur->in_units( 'weeks', 'days' ); # (0, 0) !
The last example demonstrates that there will not be any conversion between
units which don't have a fixed conversion rate. The only conversions possible
are:
For the explanation of why this is the case, please see the How DateTime Math Works section of the DateTime documentation
Note that the numbers returned by this method may not match the values given to
the constructor.
In list context, $dur->in_units returns the lengths in the order of the
units given. In scalar context, it returns the length in the first unit (but
still computes in terms of all given units).
If you need more flexibility in presenting information about durations, please
take a look a the DateTime::Format::Duration manpage.
Indicates whether or not the duration is positive, zero, or negative.
If the duration contains both positive and negative units, then it will return
false for all of these methods.
Indicates what mode is used for end of month wrapping.
Returns one of "wrap", "limit", or "preserve".
Returns a new object with the same calendar delta (months and days only) and
end of month mode as the current object.
Returns a new object with the same clock deltas (minutes, seconds, and
nanoseconds) and end of month mode as the current object.
Returns a new object with the same deltas as the current object, but multiplied
by -1. The end of month mode for the new object will be the default end of
month mode, which depends on whether the new duration is positive or negative.
You can set the end of month mode in the inverted duration explicitly by
passing an end_of_month parameter to the $dur->inverse method.
Adds or subtracts one duration from another.
These accept either constructor parameters for a new DateTime::Duration
object or an already-constructed duration object.
Multiplies each unit in the DateTime::Duration object by the specified
integer number.
This is a class method that can be used to compare or sort durations.
Comparison is done by adding each duration to the specified DateTime object
and comparing the resulting datetimes. This is necessary because without a
base, many durations are not comparable. For example, 1 month may or may not be
longer than 29 days, depending on what datetime it is added to.
If no base datetime is given, then the result of DateTime->now is used
instead. Using this default will give non-repeatable results if used to compare
two duration objects containing different units. It will also give
non-repeatable results if the durations contain multiple types of units, such
as months and days.
However, if you know that both objects only consist of one type of unit (months
or days or hours, etc.), and each duration contains the same type of
unit, then the results of the comparison will be repeatable.
These methods provide the information DateTime needs for doing date math.
The numbers returned may be positive or negative. This is mostly useful for
doing date math in DateTime.
Returns a hash with the keys ``months'', ``days'', ``minutes'', ``seconds'', and
``nanoseconds'', containing all the delta information for the object. This is
mostly useful for doing date math in DateTime.
These methods return numbers indicating how many of the given unit the object
represents, after having done a conversion to any larger units. For example,
days are first converted to weeks, and then the remainder is returned. These
numbers are always positive.
Here's what each method returns:
$dur->years == abs( $dur->in_units('years') )
$dur->months == abs( ( $dur->in_units( 'months', 'years' ) )[0] )
$dur->weeks == abs( $dur->in_units( 'weeks' ) )
$dur->days == abs( ( $dur->in_units( 'days', 'weeks' ) )[0] )
$dur->hours == abs( $dur->in_units( 'hours' ) )
$dur->minutes == abs( ( $dur->in_units( 'minutes', 'hours' ) )[0] )
$dur->seconds == abs( $dur->in_units( 'seconds' ) )
$dur->nanoseconds == abs( ( $dur->in_units( 'nanoseconds', 'seconds' ) )[0] )
If this seems confusing, remember that you can always use the <
$dur-in_units >> method to specify exactly what you want.
Better yet, if you are trying to generate output suitable for humans, use the
DateTime::Format::Duration module.
This class overloads addition, subtraction, and mutiplication.
Comparison is not overloaded. If you attempt to compare durations using <
<= >> or cmp, then an exception will be thrown! Use the compare class
method instead.
datetime@perl.org mailing list
Support for this module is provided via the datetime@perl.org email list. See
http://lists.perl.org/ for more details.
Bugs may be submitted at https://github.com/houseabsolute/DateTime.pm/issues.
There is a mailing list available for users of this distribution,
mailto:datetime@perl.org.
The source code repository for DateTime can be found at https://github.com/houseabsolute/DateTime.pm.
Dave Rolsky <autarch@urth.org>
This software is Copyright (c) 2003 - 2021 by Dave Rolsky.
This is free software, licensed under:
The Artistic License 2.0 (GPL Compatible)
The full text of the license can be found in the
LICENSE file included with this distribution.
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