role Dateish

Object that can be treated as a date

role Dateish { ... }

Both Date and DateTime support accessing of the year, month and day-of-month represented in the object, as well as related functionality such as calculating the day of the week.

Methods

method year

Defined as:

method year(Date:D: --> Int:D)

Returns the year of the date.

say Date.new('2015-12-31').year;                                  # OUTPUT: «2015␤» 
say DateTime.new(date => Date.new('2015-12-24'), hour => 1).year# OUTPUT: «2015␤»

method month

Defined as:

method month(Date:D: --> Int:D)

Returns the month of the date (1..12).

say Date.new('2015-12-31').month;                                  # OUTPUT: «12␤» 
say DateTime.new(date => Date.new('2015-12-24'), hour => 1).month# OUTPUT: «12␤»

method day

Defined as:

method day(Date:D: --> Int:D)

Returns the day of the month of the date (1..31).

say Date.new('2015-12-31').day;                                  # OUTPUT: «31␤» 
say DateTime.new(date => Date.new('2015-12-24'), hour => 1).day# OUTPUT: «24␤»

method formatter

Defined as:

method formatter(Dateish:D:)

Returns the formatting function which is used for conversion to Str. If none was provided at object construction, a default formatter is used. In that case the method will return a Callable type object.

The formatting function is called by DateTime method Str with the invocant as its only argument.

my $dt = Date.new('2015-12-31');  # (no formatter specified) 
say $dt.formatter.^name;          # OUTPUT: «Callable␤» 
my $us-format = sub ($self{ sprintf "%02d/%02d/%04d".month.day.year given $self};
$dt = Date.new('2015-12-31'formatter => $us-format);
say $dt.formatter.^name;           # OUTPUT: «Sub␤» 
say $dt;                          # OUTPUT: «12/31/2015␤»

method is-leap-year

Defined as:

method is-leap-year(Dateish:D: --> Bool:D)

Returns True if the year of the Dateish object is a leap year.

say DateTime.new(:year<2016>).is-leap-year# OUTPUT: «True␤» 
say Date.new("1900-01-01").is-leap-year;    # OUTPUT: «False␤»

method day-of-month

Defined as:

method day-of-month(Date:D: --> Int:D)

Returns the day of the month of the date (1..31). Synonymous to the day method.

say Date.new('2015-12-31').day-of-month;                                  # OUTPUT: «31␤» 
say DateTime.new(date => Date.new('2015-12-24'), hour => 1).day-of-month# OUTPUT: «24␤»

method day-of-week

Defined as:

method day-of-week(Date:D: --> Int:D)

Returns the day of the week, where 1 is Monday, 2 is Tuesday and Sunday is 7.

say Date.new('2015-12-31').day-of-week;                                  # OUTPUT: «4␤» 
say DateTime.new(date => Date.new('2015-12-24'), hour => 1).day-of-week# OUTPUT: «4␤»

method day-of-year

Defined as:

method day-of-year(Date:D: --> Int:D)

Returns the day of the year (1..366).

say Date.new('2015-12-31').day-of-year;                                  # OUTPUT: «365␤» 
say DateTime.new(date => Date.new('2015-03-24'), hour => 1).day-of-year# OUTPUT: «83␤»

method days-in-month

Defined as:

method days-in-month(Dateish:D: --> Int:D)

Returns the number of days in the month represented by the Dateish object:

say Date.new("2016-01-02").days-in-month;                # OUTPUT: «31␤» 
say DateTime.new(:year<10000>:month<2>).days-in-month# OUTPUT: «29␤»

method week

Defined as:

method week()

Returns a list of two integers: the year, and the week number. This is because at the start or end of a year, the week may actually belong to the other year.

my ($year$week= Date.new("2014-12-31").week;
say $year;                       # OUTPUT: «2015␤» 
say $week;                       # OUTPUT: «1␤» 
say Date.new('2015-01-31').week# OUTPUT: «(2015 5)␤»

method week-number

Defined as:

method week-number(Date:D: --> Int:D)

Returns the week number (1..53) of the date specified by the invocant. The first week of the year is defined by ISO as the one which contains the fourth day of January. Thus, dates early in January often end up in the last week of the prior year, and similarly, the final few days of December may be placed in the first week of the next year.

say Date.new("2014-12-31").week-number;   # 1  (first week of 2015) 
say Date.new("2016-01-02").week-number;   # 53 (last week of 2015)

method week-year

Defined as:

method week-year(Date:D: --> Int:D)

Returns the week year of the date specified by the invocant. Normally week-year is equal to Date.year. Note however that dates early in January often end up in the last week of the prior year, and similarly, the final few days of December may be placed in the first week of the next year.

say Date.new("2015-11-15").week-year;   # 2015 
say Date.new("2014-12-31").week-year;   # 2015 (date belongs to the first week of 2015) 
say Date.new("2016-01-02").week-year;   # 2015 (date belongs to the last week of 2015)

method weekday-of-month

Defined as:

method weekday-of-month(Date:D: --> Int:D)

Returns a number (1..5) indicating the number of times a particular day-of-week has occurred so far during that month, the day itself included.

say Date.new("2003-06-09").weekday-of-month;  # 2  (second Monday of the month)

method yyyy-mm-dd

Defined as:

method yyyy-mm-dd(str $sep = "-" --> Str:D)

Returns the date in YYYY-MM-DD format (ISO 8601). The optional positional argument $sep, which defaults to -, is a one-character separator placed between the different parts of the date.

say Date.new("2015-11-15").yyyy-mm-dd;   # OUTPUT: «2015-11-15␤» 
say DateTime.new(1470853583).yyyy-mm-dd# OUTPUT: «2016-08-10␤» 
say Date.today.yyyy-mm-dd("/");          # OUTPUT: «2020/03/14␤» 

method mm-dd-yyyy

Defined as:

method mm-dd-yyyy(str $sep = "-" --> Str:D)

Returns the date in MM-DD-YYYY format (ISO 8601). The optional positional argument $sep, which defaults to -, is a one-character separator placed between the different parts of the date.

say Date.new("2015-11-15").mm-dd-yyyy;   # OUTPUT: «11-15-2015␤» 
say DateTime.new(1470853583).mm-dd-yyyy# OUTPUT: «08-10-2016␤» 
say Date.today.mm-dd-yyyy("/");          # OUTPUT: «03/14/2020␤» 

method dd-mm-yyyy

Defined as:

method dd-mm-yyyy(str $sep = "-" --> Str:D)

Returns the date in DD-MM-YYYY format (ISO 8601). The optional positional argument $sep, which defaults to -, is a one-character separator placed between the different parts of the date.

say Date.new("2015-11-15").dd-mm-yyyy;    # OUTPUT: «15-11-2015␤» 
say DateTime.new(1470853583).dd-mm-yyyy;  # OUTPUT: «10-08-2016␤» 
say Date.today.dd-mm-yyyy("/");           # OUTPUT: «14/03/2020␤» 

method daycount

Defined as:

method daycount(Dateish:D: --> Int:D)

Returns the number of days from the epoch Nov. 17, 1858, to the day of the invocant. The daycount returned by this method is the integral part of the Modified Julian Day (MJD) which is used routinely by astronomers, geodesists, scientists, and others. The MJD convention is designed to facilitate simplified chronological calculations. The fractional part of the MJD consists of the hours, minutes, and seconds of the using DateTime object converted to the equivalent fraction of 24 hours. Those two values added define the MJD of that instant.

say Date.new('1995-09-27').daycount;    # OUTPUT: «49987␤»

method IO

Defined as:

method IO(Dateish:D: --> IO::Path:D)

Returns an IO::Path object representing the stringified value of the Dateish object:

Date.today.IO.say;   # OUTPUT: «"2016-10-03".IO␤» 
DateTime.now.IO.say# OUTPUT: «"2016-10-03T11:14:47.977994-04:00".IO␤»

PORTABILITY NOTE: some operating systems (e.g. Windows) do not permit colons (:) in filenames, which would be present in IO::Path created from a DateTime object.

method earlier

Defined as:

multi method earlier(Dateish:D: *%unit)
multi method earlier(Dateish:D: @pairs)

Returns an object based on the current one, but with a date delta towards the past applied. Unless the given unit is second or seconds, the given value will be converted to an Int. See .later for usage. It will generally be used through classes that implement this role, Date or DateTime

my $d = Date.new('2015-02-27');
say $d.earlier(month => 5).earlier(:2days);  # OUTPUT: «2014-09-25␤» 
my $d = DateTime.new(date => Date.new('2015-02-27'));
say $d.earlier(month => 1).earlier(:2days);  # OUTPUT: «2015-01-25T00:00:00Z␤»

If the resultant time has value 60 for seconds, yet no leap second actually exists for that time, seconds will be set to 59:

say DateTime.new('2008-12-31T23:59:60Z').earlier: :1day;
# OUTPUT: «2008-12-30T23:59:59Z␤»

Negative offsets are allowed, though later is more idiomatic for that.

If you need to use more than one unit, you will need to build them into a List of Pairs to use the second form of the method:

say Date.new('2021-03-31').earlier(  ( year => 3month => 2day => 8 ) ); # OUTPUT: «2018-01-23␤» 

This feature was introduced in release 2021.02 of the Rakudo compiler.

method later

Defined as:

multi method later(DateTime:D: *%unit)

Returns an object based on the current one (belonging to any class that mixes this role in), but with a time delta applied. The time delta can be passed as a named argument where the argument name is the unit.

Unless the given unit is second or seconds, the given value will be converted to an Int.

Allowed units are second, seconds, minute, minutes, hour, hours, day, days, week, weeks, month, months, year, years. Please note that the plural forms can only be used with the later and earlier methods.

The :2nd form of colonpairs can be used as a compact and self-documenting way of specifying the delta:

say DateTime.new('2015-12-24T12:23:00Z').later(:2years);
# OUTPUT: «2017-12-24T12:23:00Z␤»

Since addition of several different time units is not commutative, only one unit may be passed (and the first multi will be used).

my $d = DateTime.new(date => Date.new('2015-02-27'));
say $d.later(month => 1).later(:2days);  # OUTPUT: «2015-03-29T00:00:00Z␤» 
say $d.later(days => 2).later(:1month);  # OUTPUT: «2015-04-01T00:00:00Z␤» 
say $d.later(days => 2).later(:month);   # same, as +True === 1

You can also (since release 2021.02 of the Rakudo compiler) pass several units at the same time, but you will have to join them in a List to activate the second form:

say DateTime.new(date => Date.new('2015-02-27')).later( (:1month, :2days) )
# OUTPUT: «2015-03-29T00:00:00Z␤» 

If the resultant time has value 60 for seconds, yet no leap second actually exists for that time, seconds will be set to 59:

say DateTime.new('2008-12-31T23:59:60Z').later: :1day;
# OUTPUT: «2009-01-01T23:59:59Z␤»

Negative offsets are allowed, though earlier is more idiomatic for that.

Objects of type Date will behave in the same way:

my $d = Date.new('2015-02-27');
say $d.later(month => 1).later(:2days);  # OUTPUT: «2015-03-29␤» 
say $d.later(days => 2).later(:1month);  # OUTPUT: «2015-04-01␤» 
say $d.later(days => 2).later(:month);   # same, as +True === 1 

Type Graph

Type relations for Dateish
perl6-type-graph Dateish Dateish Mu Mu Any Any Any->Mu DateTime DateTime DateTime->Dateish DateTime->Any Date Date Date->Dateish Date->Any

Expand above chart