date_time_ext_test.rb

require 'abstract_unit'
require 'active_support/time'
require 'core_ext/date_and_time_behavior'
require 'time_zone_test_helpers'

class DateTimeExtCalculationsTest < ActiveSupport::TestCase
  def date_time_init(year,month,day,hour,minute,second,*args)
    DateTime.civil(year,month,day,hour,minute,second)
  end

  include DateAndTimeBehavior
  include TimeZoneTestHelpers

  def test_to_s
    datetime = DateTime.new(2005, 2, 21, 14, 30, 0, 0)
    assert_equal "2005-02-21 14:30:00",               datetime.to_s(:db)
    assert_equal "14:30",                             datetime.to_s(:time)
    assert_equal "21 Feb 14:30",                      datetime.to_s(:short)
    assert_equal "February 21, 2005 14:30",           datetime.to_s(:long)
    assert_equal "Mon, 21 Feb 2005 14:30:00 +0000",   datetime.to_s(:rfc822)
    assert_equal "February 21st, 2005 14:30",         datetime.to_s(:long_ordinal)
    assert_match(/^2005-02-21T14:30:00(Z|\+00:00)$/,  datetime.to_s)

    with_env_tz "US/Central" do
      assert_equal "2009-02-05T14:30:05-06:00", DateTime.civil(2009, 2, 5, 14, 30, 5, Rational(-21600, 86400)).to_s(:iso8601)
      assert_equal "2008-06-09T04:05:01-05:00", DateTime.civil(2008, 6, 9, 4, 5, 1, Rational(-18000, 86400)).to_s(:iso8601)
      assert_equal "2009-02-05T14:30:05+00:00", DateTime.civil(2009, 2, 5, 14, 30, 5).to_s(:iso8601)
    end
  end

  def test_readable_inspect
    datetime = DateTime.new(2005, 2, 21, 14, 30, 0)
    assert_equal "Mon, 21 Feb 2005 14:30:00 +0000", datetime.readable_inspect
    assert_equal datetime.readable_inspect, datetime.inspect
  end

  def test_custom_date_format
    Time::DATE_FORMATS[:custom] = '%Y%m%d%H%M%S'
    assert_equal '20050221143000', DateTime.new(2005, 2, 21, 14, 30, 0).to_s(:custom)
    Time::DATE_FORMATS.delete(:custom)
  end

  def test_to_date
    assert_equal Date.new(2005, 2, 21), DateTime.new(2005, 2, 21, 14, 30, 0).to_date
  end

  def test_to_datetime
    assert_equal DateTime.new(2005, 2, 21, 14, 30, 0), DateTime.new(2005, 2, 21, 14, 30, 0).to_datetime
  end

  def test_to_time
    with_env_tz 'US/Eastern' do
      assert_equal Time, DateTime.new(2005, 2, 21, 10, 11, 12, 0).to_time.class
      assert_equal Time.local(2005, 2, 21, 5, 11, 12), DateTime.new(2005, 2, 21, 10, 11, 12, 0).to_time
      assert_equal Time.local(2005, 2, 21, 5, 11, 12).utc_offset, DateTime.new(2005, 2, 21, 10, 11, 12, 0).to_time.utc_offset
    end
  end

  def test_to_time_preserves_fractional_seconds
    assert_equal Time.utc(2005, 2, 21, 10, 11, 12, 256), DateTime.new(2005, 2, 21, 10, 11, 12 + Rational(256, 1000000), 0).to_time
  end

  def test_civil_from_format
    assert_equal Time.local(2010, 5, 4, 0, 0, 0), DateTime.civil_from_format(:local, 2010, 5, 4)
    assert_equal Time.utc(2010, 5, 4, 0, 0, 0), DateTime.civil_from_format(:utc, 2010, 5, 4)
  end

  def test_seconds_since_midnight
    assert_equal 1,DateTime.civil(2005,1,1,0,0,1).seconds_since_midnight
    assert_equal 60,DateTime.civil(2005,1,1,0,1,0).seconds_since_midnight
    assert_equal 3660,DateTime.civil(2005,1,1,1,1,0).seconds_since_midnight
    assert_equal 86399,DateTime.civil(2005,1,1,23,59,59).seconds_since_midnight
  end

  def test_seconds_until_end_of_day
    assert_equal 0, DateTime.civil(2005,1,1,23,59,59).seconds_until_end_of_day
    assert_equal 1, DateTime.civil(2005,1,1,23,59,58).seconds_until_end_of_day
    assert_equal 60, DateTime.civil(2005,1,1,23,58,59).seconds_until_end_of_day
    assert_equal 3660, DateTime.civil(2005,1,1,22,58,59).seconds_until_end_of_day
    assert_equal 86399, DateTime.civil(2005,1,1,0,0,0).seconds_until_end_of_day
  end

  def test_beginning_of_day
    assert_equal DateTime.civil(2005,2,4,0,0,0), DateTime.civil(2005,2,4,10,10,10).beginning_of_day
  end

  def test_middle_of_day
    assert_equal DateTime.civil(2005,2,4,12,0,0), DateTime.civil(2005,2,4,10,10,10).middle_of_day
  end

  def test_end_of_day
    assert_equal DateTime.civil(2005,2,4,23,59,59), DateTime.civil(2005,2,4,10,10,10).end_of_day
  end

  def test_beginning_of_hour
    assert_equal DateTime.civil(2005,2,4,19,0,0), DateTime.civil(2005,2,4,19,30,10).beginning_of_hour
  end

  def test_end_of_hour
    assert_equal DateTime.civil(2005,2,4,19,59,59), DateTime.civil(2005,2,4,19,30,10).end_of_hour
  end

  def test_beginning_of_minute
    assert_equal DateTime.civil(2005,2,4,19,30,0), DateTime.civil(2005,2,4,19,30,10).beginning_of_minute
  end

  def test_end_of_minute
    assert_equal DateTime.civil(2005,2,4,19,30,59), DateTime.civil(2005,2,4,19,30,10).end_of_minute
  end

  def test_end_of_month
    assert_equal DateTime.civil(2005,3,31,23,59,59), DateTime.civil(2005,3,20,10,10,10).end_of_month
    assert_equal DateTime.civil(2005,2,28,23,59,59), DateTime.civil(2005,2,20,10,10,10).end_of_month
    assert_equal DateTime.civil(2005,4,30,23,59,59), DateTime.civil(2005,4,20,10,10,10).end_of_month
  end

  def test_last_year
    assert_equal DateTime.civil(2004,6,5,10),  DateTime.civil(2005,6,5,10,0,0).last_year
  end

  def test_ago
    assert_equal DateTime.civil(2005,2,22,10,10,9),  DateTime.civil(2005,2,22,10,10,10).ago(1)
    assert_equal DateTime.civil(2005,2,22,9,10,10),  DateTime.civil(2005,2,22,10,10,10).ago(3600)
    assert_equal DateTime.civil(2005,2,20,10,10,10), DateTime.civil(2005,2,22,10,10,10).ago(86400*2)
    assert_equal DateTime.civil(2005,2,20,9,9,45),   DateTime.civil(2005,2,22,10,10,10).ago(86400*2 + 3600 + 25)
  end

  def test_since
    assert_equal DateTime.civil(2005,2,22,10,10,11), DateTime.civil(2005,2,22,10,10,10).since(1)
    assert_equal DateTime.civil(2005,2,22,11,10,10), DateTime.civil(2005,2,22,10,10,10).since(3600)
    assert_equal DateTime.civil(2005,2,24,10,10,10), DateTime.civil(2005,2,22,10,10,10).since(86400*2)
    assert_equal DateTime.civil(2005,2,24,11,10,35), DateTime.civil(2005,2,22,10,10,10).since(86400*2 + 3600 + 25)
    assert_equal DateTime.civil(2005,2,22,10,10,11), DateTime.civil(2005,2,22,10,10,10).since(1.333)
    assert_equal DateTime.civil(2005,2,22,10,10,12), DateTime.civil(2005,2,22,10,10,10).since(1.667)
  end

  def test_change
    assert_equal DateTime.civil(2006,2,22,15,15,10), DateTime.civil(2005,2,22,15,15,10).change(:year => 2006)
    assert_equal DateTime.civil(2005,6,22,15,15,10), DateTime.civil(2005,2,22,15,15,10).change(:month => 6)
    assert_equal DateTime.civil(2012,9,22,15,15,10), DateTime.civil(2005,2,22,15,15,10).change(:year => 2012, :month => 9)
    assert_equal DateTime.civil(2005,2,22,16),       DateTime.civil(2005,2,22,15,15,10).change(:hour => 16)
    assert_equal DateTime.civil(2005,2,22,16,45),    DateTime.civil(2005,2,22,15,15,10).change(:hour => 16, :min => 45)
    assert_equal DateTime.civil(2005,2,22,15,45),    DateTime.civil(2005,2,22,15,15,10).change(:min => 45)

    # datetime with fractions of a second
    assert_equal DateTime.civil(2005,2,1,15,15,10.7), DateTime.civil(2005,2,22,15,15,10.7).change(:day => 1)
  end

  def test_advance
    assert_equal DateTime.civil(2006,2,28,15,15,10),  DateTime.civil(2005,2,28,15,15,10).advance(:years => 1)
    assert_equal DateTime.civil(2005,6,28,15,15,10),  DateTime.civil(2005,2,28,15,15,10).advance(:months => 4)
    assert_equal DateTime.civil(2005,3,21,15,15,10),  DateTime.civil(2005,2,28,15,15,10).advance(:weeks => 3)
    assert_equal DateTime.civil(2005,3,5,15,15,10),   DateTime.civil(2005,2,28,15,15,10).advance(:days => 5)
    assert_equal DateTime.civil(2012,9,28,15,15,10),  DateTime.civil(2005,2,28,15,15,10).advance(:years => 7, :months => 7)
    assert_equal DateTime.civil(2013,10,3,15,15,10),  DateTime.civil(2005,2,28,15,15,10).advance(:years => 7, :months => 19, :days => 5)
    assert_equal DateTime.civil(2013,10,17,15,15,10), DateTime.civil(2005,2,28,15,15,10).advance(:years => 7, :months => 19, :weeks => 2, :days => 5)
    assert_equal DateTime.civil(2001,12,27,15,15,10), DateTime.civil(2005,2,28,15,15,10).advance(:years => -3, :months => -2, :days => -1)
    assert_equal DateTime.civil(2005,2,28,15,15,10),  DateTime.civil(2004,2,29,15,15,10).advance(:years => 1) #leap day plus one year
    assert_equal DateTime.civil(2005,2,28,20,15,10),  DateTime.civil(2005,2,28,15,15,10).advance(:hours => 5)
    assert_equal DateTime.civil(2005,2,28,15,22,10),  DateTime.civil(2005,2,28,15,15,10).advance(:minutes => 7)
    assert_equal DateTime.civil(2005,2,28,15,15,19),  DateTime.civil(2005,2,28,15,15,10).advance(:seconds => 9)
    assert_equal DateTime.civil(2005,2,28,20,22,19),  DateTime.civil(2005,2,28,15,15,10).advance(:hours => 5, :minutes => 7, :seconds => 9)
    assert_equal DateTime.civil(2005,2,28,10,8,1),    DateTime.civil(2005,2,28,15,15,10).advance(:hours => -5, :minutes => -7, :seconds => -9)
    assert_equal DateTime.civil(2013,10,17,20,22,19), DateTime.civil(2005,2,28,15,15,10).advance(:years => 7, :months => 19, :weeks => 2, :days => 5, :hours => 5, :minutes => 7, :seconds => 9)
  end

  def test_advance_partial_days
    assert_equal DateTime.civil(2012,9,29,13,15,10),  DateTime.civil(2012,9,28,1,15,10).advance(:days => 1.5)
    assert_equal DateTime.civil(2012,9,28,13,15,10),  DateTime.civil(2012,9,28,1,15,10).advance(:days => 0.5)
    assert_equal DateTime.civil(2012,10,29,13,15,10), DateTime.civil(2012,9,28,1,15,10).advance(:days => 1.5, :months => 1)
  end

  def test_advanced_processes_first_the_date_deltas_and_then_the_time_deltas
    # If the time deltas were processed first, the following datetimes would be advanced to 2010/04/01 instead.
    assert_equal DateTime.civil(2010, 3, 29), DateTime.civil(2010, 2, 28, 23, 59, 59).advance(:months => 1, :seconds => 1)
    assert_equal DateTime.civil(2010, 3, 29), DateTime.civil(2010, 2, 28, 23, 59).advance(:months => 1, :minutes => 1)
    assert_equal DateTime.civil(2010, 3, 29), DateTime.civil(2010, 2, 28, 23).advance(:months => 1, :hours => 1)
    assert_equal DateTime.civil(2010, 3, 29), DateTime.civil(2010, 2, 28, 22, 58, 59).advance(:months => 1, :hours => 1, :minutes => 1, :seconds => 1)
  end

  def test_last_week
    assert_equal DateTime.civil(2005,2,21), DateTime.civil(2005,3,1,15,15,10).last_week
    assert_equal DateTime.civil(2005,2,22), DateTime.civil(2005,3,1,15,15,10).last_week(:tuesday)
    assert_equal DateTime.civil(2005,2,25), DateTime.civil(2005,3,1,15,15,10).last_week(:friday)
    assert_equal DateTime.civil(2006,10,30), DateTime.civil(2006,11,6,0,0,0).last_week
    assert_equal DateTime.civil(2006,11,15), DateTime.civil(2006,11,23,0,0,0).last_week(:wednesday)
  end

  def test_date_time_should_have_correct_last_week_for_leap_year
    assert_equal DateTime.civil(2016, 2, 29), DateTime.civil(2016, 3, 7).last_week
  end

  def test_last_month_on_31st
    assert_equal DateTime.civil(2004, 2, 29), DateTime.civil(2004, 3, 31).last_month
  end

  def test_last_quarter_on_31st
    assert_equal DateTime.civil(2004, 2, 29), DateTime.civil(2004, 5, 31).last_quarter
  end

  def test_xmlschema
    assert_match(/^1880-02-28T15:15:10\+00:?00$/, DateTime.civil(1880, 2, 28, 15, 15, 10).xmlschema)
    assert_match(/^1980-02-28T15:15:10\+00:?00$/, DateTime.civil(1980, 2, 28, 15, 15, 10).xmlschema)
    assert_match(/^2080-02-28T15:15:10\+00:?00$/, DateTime.civil(2080, 2, 28, 15, 15, 10).xmlschema)
    assert_match(/^1880-02-28T15:15:10-06:?00$/, DateTime.civil(1880, 2, 28, 15, 15, 10, -0.25).xmlschema)
    assert_match(/^1980-02-28T15:15:10-06:?00$/, DateTime.civil(1980, 2, 28, 15, 15, 10, -0.25).xmlschema)
    assert_match(/^2080-02-28T15:15:10-06:?00$/, DateTime.civil(2080, 2, 28, 15, 15, 10, -0.25).xmlschema)
  end

  def test_today_with_offset
    Date.stub(:current, Date.new(2000, 1, 1)) do
      assert_equal false, DateTime.civil(1999,12,31,23,59,59, Rational(-18000, 86400)).today?
      assert_equal true,  DateTime.civil(2000,1,1,0,0,0, Rational(-18000, 86400)).today?
      assert_equal true,  DateTime.civil(2000,1,1,23,59,59, Rational(-18000, 86400)).today?
      assert_equal false, DateTime.civil(2000,1,2,0,0,0, Rational(-18000, 86400)).today?
    end
  end

  def test_today_without_offset
    Date.stub(:current, Date.new(2000, 1, 1)) do
      assert_equal false, DateTime.civil(1999,12,31,23,59,59).today?
      assert_equal true,  DateTime.civil(2000,1,1,0).today?
      assert_equal true,  DateTime.civil(2000,1,1,23,59,59).today?
      assert_equal false, DateTime.civil(2000,1,2,0).today?
    end
  end

  def test_past_with_offset
    DateTime.stub(:current, DateTime.civil(2005,2,10,15,30,45, Rational(-18000, 86400))) do
      assert_equal true,  DateTime.civil(2005,2,10,15,30,44, Rational(-18000, 86400)).past?
      assert_equal false,  DateTime.civil(2005,2,10,15,30,45, Rational(-18000, 86400)).past?
      assert_equal false,  DateTime.civil(2005,2,10,15,30,46, Rational(-18000, 86400)).past?
    end
  end

  def test_past_without_offset
    DateTime.stub(:current, DateTime.civil(2005,2,10,15,30,45, Rational(-18000, 86400))) do
      assert_equal true,  DateTime.civil(2005,2,10,20,30,44).past?
      assert_equal false,  DateTime.civil(2005,2,10,20,30,45).past?
      assert_equal false,  DateTime.civil(2005,2,10,20,30,46).past?
    end
  end

  def test_future_with_offset
    DateTime.stub(:current, DateTime.civil(2005,2,10,15,30,45, Rational(-18000, 86400))) do
      assert_equal false,  DateTime.civil(2005,2,10,15,30,44, Rational(-18000, 86400)).future?
      assert_equal false,  DateTime.civil(2005,2,10,15,30,45, Rational(-18000, 86400)).future?
      assert_equal true,  DateTime.civil(2005,2,10,15,30,46, Rational(-18000, 86400)).future?
    end
  end

  def test_future_without_offset
    DateTime.stub(:current, DateTime.civil(2005,2,10,15,30,45, Rational(-18000, 86400))) do
      assert_equal false,  DateTime.civil(2005,2,10,20,30,44).future?
      assert_equal false,  DateTime.civil(2005,2,10,20,30,45).future?
      assert_equal true,  DateTime.civil(2005,2,10,20,30,46).future?
    end
  end

  def test_current_returns_date_today_when_zone_is_not_set
    with_env_tz 'US/Eastern' do
      Time.stub(:now, Time.local(1999, 12, 31, 23, 59, 59)) do
        assert_equal DateTime.new(1999, 12, 31, 23, 59, 59, Rational(-18000, 86400)), DateTime.current
      end
    end
  end

  def test_current_returns_time_zone_today_when_zone_is_set
    Time.zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
    with_env_tz 'US/Eastern' do
      Time.stub(:now, Time.local(1999, 12, 31, 23, 59, 59)) do
        assert_equal DateTime.new(1999, 12, 31, 23, 59, 59, Rational(-18000, 86400)), DateTime.current
      end
    end
  ensure
    Time.zone = nil
  end

  def test_current_without_time_zone
    assert_kind_of DateTime, DateTime.current
  end

  def test_current_with_time_zone
    with_env_tz 'US/Eastern' do
      assert_kind_of DateTime, DateTime.current
    end
  end

  def test_acts_like_date
    assert DateTime.new.acts_like_date?
  end

  def test_acts_like_time
    assert DateTime.new.acts_like_time?
  end

  def test_utc?
    assert_equal true, DateTime.civil(2005, 2, 21, 10, 11, 12).utc?
    assert_equal true, DateTime.civil(2005, 2, 21, 10, 11, 12, 0).utc?
    assert_equal false, DateTime.civil(2005, 2, 21, 10, 11, 12, 0.25).utc?
    assert_equal false, DateTime.civil(2005, 2, 21, 10, 11, 12, -0.25).utc?
  end

  def test_utc_offset
    assert_equal 0, DateTime.civil(2005, 2, 21, 10, 11, 12).utc_offset
    assert_equal 0, DateTime.civil(2005, 2, 21, 10, 11, 12, 0).utc_offset
    assert_equal 21600, DateTime.civil(2005, 2, 21, 10, 11, 12, 0.25).utc_offset
    assert_equal( -21600, DateTime.civil(2005, 2, 21, 10, 11, 12, -0.25).utc_offset )
    assert_equal( -18000, DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-5, 24)).utc_offset )
  end

  def test_utc
    assert_equal DateTime.civil(2005, 2, 21, 16, 11, 12, 0), DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-6, 24)).utc
    assert_equal DateTime.civil(2005, 2, 21, 15, 11, 12, 0), DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-5, 24)).utc
    assert_equal DateTime.civil(2005, 2, 21, 10, 11, 12, 0), DateTime.civil(2005, 2, 21, 10, 11, 12, 0).utc
    assert_equal DateTime.civil(2005, 2, 21, 9, 11, 12, 0), DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(1, 24)).utc
    assert_equal DateTime.civil(2005, 2, 21, 9, 11, 12, 0), DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(1, 24)).getutc
  end

  def test_formatted_offset_with_utc
    assert_equal '+00:00', DateTime.civil(2000).formatted_offset
    assert_equal '+0000', DateTime.civil(2000).formatted_offset(false)
    assert_equal 'UTC', DateTime.civil(2000).formatted_offset(true, 'UTC')
  end

  def test_formatted_offset_with_local
    dt = DateTime.civil(2005, 2, 21, 10, 11, 12, Rational(-5, 24))
    assert_equal '-05:00', dt.formatted_offset
    assert_equal '-0500', dt.formatted_offset(false)
  end

  def test_compare_with_time
    assert_equal  1, DateTime.civil(2000) <=> Time.utc(1999, 12, 31, 23, 59, 59)
    assert_equal  0, DateTime.civil(2000) <=> Time.utc(2000, 1, 1, 0, 0, 0)
    assert_equal(-1, DateTime.civil(2000) <=> Time.utc(2000, 1, 1, 0, 0, 1))
  end

  def test_compare_with_datetime
    assert_equal  1, DateTime.civil(2000) <=> DateTime.civil(1999, 12, 31, 23, 59, 59)
    assert_equal  0, DateTime.civil(2000) <=> DateTime.civil(2000, 1, 1, 0, 0, 0)
    assert_equal(-1, DateTime.civil(2000) <=> DateTime.civil(2000, 1, 1, 0, 0, 1))
  end

  def test_compare_with_time_with_zone
    assert_equal  1, DateTime.civil(2000) <=> ActiveSupport::TimeWithZone.new( Time.utc(1999, 12, 31, 23, 59, 59), ActiveSupport::TimeZone['UTC'] )
    assert_equal  0, DateTime.civil(2000) <=> ActiveSupport::TimeWithZone.new( Time.utc(2000, 1, 1, 0, 0, 0), ActiveSupport::TimeZone['UTC'] )
    assert_equal(-1, DateTime.civil(2000) <=> ActiveSupport::TimeWithZone.new( Time.utc(2000, 1, 1, 0, 0, 1), ActiveSupport::TimeZone['UTC'] ))
  end

  def test_compare_with_string
    assert_equal   1, DateTime.civil(2000) <=> Time.utc(1999, 12, 31, 23, 59, 59).to_s
    assert_equal   0, DateTime.civil(2000) <=> Time.utc(2000, 1, 1, 0, 0, 0).to_s
    assert_equal( -1, DateTime.civil(2000) <=> Time.utc(2000, 1, 1, 0, 0, 1).to_s)
    assert_equal nil, DateTime.civil(2000) <=> "Invalid as Time"
  end

  def test_compare_with_integer
    assert_equal  1, DateTime.civil(1970, 1, 1, 12, 0, 0) <=> 2440587
    assert_equal  0, DateTime.civil(1970, 1, 1, 12, 0, 0) <=> 2440588
    assert_equal(-1, DateTime.civil(1970, 1, 1, 12, 0, 0) <=> 2440589)
  end

  def test_compare_with_float
    assert_equal  1, DateTime.civil(1970) <=> 2440586.5
    assert_equal  0, DateTime.civil(1970) <=> 2440587.5
    assert_equal(-1, DateTime.civil(1970) <=> 2440588.5)
  end

  def test_compare_with_rational
    assert_equal  1, DateTime.civil(1970) <=> Rational(4881173, 2)
    assert_equal  0, DateTime.civil(1970) <=> Rational(4881175, 2)
    assert_equal(-1, DateTime.civil(1970) <=> Rational(4881177, 2))
  end

  def test_to_f
    assert_equal 946684800.0, DateTime.civil(2000).to_f
    assert_equal 946684800.0, DateTime.civil(1999,12,31,19,0,0,Rational(-5,24)).to_f
    assert_equal 946684800.5, DateTime.civil(1999,12,31,19,0,0.5,Rational(-5,24)).to_f
  end

  def test_to_i
    assert_equal 946684800, DateTime.civil(2000).to_i
    assert_equal 946684800, DateTime.civil(1999,12,31,19,0,0,Rational(-5,24)).to_i
  end

  def test_usec
    assert_equal 0, DateTime.civil(2000).usec
    assert_equal 500000, DateTime.civil(2000, 1, 1, 0, 0, Rational(1,2)).usec
  end

  def test_nsec
    assert_equal 0, DateTime.civil(2000).nsec
    assert_equal 500000000, DateTime.civil(2000, 1, 1, 0, 0, Rational(1,2)).nsec
  end
end