A subclass of
Object that includes the
Comparable module and easily handles date.
Add this line to your application's Gemfile:
And then execute:
Or install it yourself as:
$ gem install date
Date object is created with
require 'date' Date.new(2001,2,3) #=> #<Date: 2001-02-03 ...> Date.jd(2451944) #=> #<Date: 2001-02-03 ...> Date.ordinal(2001,34) #=> #<Date: 2001-02-03 ...> Date.commercial(2001,5,6) #=> #<Date: 2001-02-03 ...> Date.parse('2001-02-03') #=> #<Date: 2001-02-03 ...> Date.strptime('03-02-2001', '%d-%m-%Y') #=> #<Date: 2001-02-03 ...> Time.new(2001,2,3).to_date #=> #<Date: 2001-02-03 ...>
Date objects are immutable; hence cannot modify themselves.
The concept of a date object can be represented as a tuple of the day count, the offset and the day of calendar reform.
The day count denotes the absolute position of a temporal dimension. The offset is relative adjustment, which determines decoded local time with the day count. The day of calendar reform denotes the start day of the new style. The old style of the West is the Julian calendar which was adopted by Caesar. The new style is the Gregorian calendar, which is the current civil calendar of many countries.
The day count is virtually the astronomical Julian day number. The offset in this class is usually zero, and cannot be specified directly.
Date object can be created with an optional argument, the day of calendar reform as a Julian day number, which should be 2298874 to 2426355 or negative/positive infinity. The default value is
Date::ITALY (2299161=1582-10-15). See also sample/cal.rb.
$ ruby sample/cal.rb -c it 10 1582 October 1582 S M Tu W Th F S 1 2 3 4 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
$ ruby sample/cal.rb -c gb 9 1752 September 1752 S M Tu W Th F S 1 2 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Date object has various methods. See each reference.
d = Date.parse('3rd Feb 2001') #=> #<Date: 2001-02-03 ...> d.year #=> 2001 d.mon #=> 2 d.mday #=> 3 d.wday #=> 6 d += 1 #=> #<Date: 2001-02-04 ...> d.strftime('%a %d %b %Y') #=> "Sun 04 Feb 2001"
After checking out the repo, run
bin/setup to install dependencies. Then, run
rake test to run the tests. You can also run
bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run
bundle exec rake install. To release a new version, update the version number in
version.rb, and then run
bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the
.gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/date.
The gem is available as open source under the terms of the 2-Clause BSD License.