jruby · Jul 21, 2015 · Jul 21, 2015 · Jul 21, 2015
diff --git a/lib/ruby/1.9/date.rb b/lib/ruby/1.9/date.rb
@@ -1458,7 +1458,14 @@ def next() next_day end
   # of the returned Date will be the last day of the target month.
   def >> (n)
     n = n.to_int rescue raise(TypeError, "n must be a Fixnum")
-    self.class.new!(@dt.plusMonths(n), @of, @sg, @sub_millis)
+    y, m = ((year * 12) + (mon - 1) + n).divmod(12)
+    m, = (m + 1).divmod(1)
+    d = mday
+    until cd = _valid_civil?(y, m, d, start)
+      d -= 1
+      raise ArgumentError, "invalid date" unless d > 0
+    end
+    self + (cd - jd)
   end
 
   # Return a new Date object that is +n+ months earlier than
@@ -1473,7 +1480,7 @@ def next_month(n=1) self >> n end
   def prev_month(n=1) self << n end
 
   def next_year(n=1)
-    self.class.new!(@dt.plusYears(n.to_i), @of, @sg, @sub_millis)
+    self >> (n * 12)
   end
 
   def prev_year(n=1)

diff --git a/spec/ruby/library/date/add_month_spec.rb b/spec/ruby/library/date/add_month_spec.rb
@@ -12,6 +12,14 @@
     d.should == Date.civil(2008, 4, 30)
   end
 
+  it "returns the day of the reform if date falls within calendar reform" do
+    calendar_reform_italy = Date.new(1582, 10, 4)
+    d1 = Date.new(1582, 9, 9) >> 1
+    d2 = Date.new(1582, 9, 10) >> 1
+    d1.should == calendar_reform_italy
+    d2.should == calendar_reform_italy
+  end
+
   it "raise a TypeError when passed a Symbol" do
     lambda { Date.civil(2007,2,27) >> :hello }.should raise_error(TypeError)
   end

diff --git a/spec/ruby/library/date/next_year_spec.rb b/spec/ruby/library/date/next_year_spec.rb
@@ -0,0 +1,12 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require 'date'
+
+describe "Date#next_year" do
+  it "returns the day of the reform if date falls within calendar reform" do
+    calendar_reform_italy = Date.new(1582, 10, 4)
+    d1 = Date.new(1581, 10, 9).next_year
+    d2 = Date.new(1581, 10, 10).next_year
+    d1.should == calendar_reform_italy
+    d2.should == calendar_reform_italy
+  end
+end
diff --git a/spec/ruby/library/date/prev_year_spec.rb b/spec/ruby/library/date/prev_year_spec.rb
@@ -0,0 +1,12 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require 'date'
+
+describe "Date#prev_year" do
+  it "returns the day of the reform if date falls within calendar reform" do
+    calendar_reform_italy = Date.new(1582, 10, 4)
+    d1 = Date.new(1583, 10, 9).prev_year
+    d2 = Date.new(1583, 10, 10).prev_year
+    d1.should == calendar_reform_italy
+    d2.should == calendar_reform_italy
+  end
+end
diff --git a/spec/tags/1.8/ruby/library/date/add_month_tags.txt b/spec/tags/1.8/ruby/library/date/add_month_tags.txt
@@ -0,0 +1 @@
+fails:Date#>> returns the day of the reform if date falls within calendar reform
diff --git a/spec/tags/1.8/ruby/library/date/next_year_tags.txt b/spec/tags/1.8/ruby/library/date/next_year_tags.txt
@@ -0,0 +1 @@
+fails:Date#next_year returns the day of the reform if date falls within calendar reform
diff --git a/spec/tags/1.8/ruby/library/date/prev_year_tags.txt b/spec/tags/1.8/ruby/library/date/prev_year_tags.txt
@@ -0,0 +1 @@
+fails:Date#prev_year returns the day of the reform if date falls within calendar reform
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		fails:Date#>> returns the day of the reform if date falls within calendar reform
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		fails:Date#next_year returns the day of the reform if date falls within calendar reform
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		fails:Date#prev_year returns the day of the reform if date falls within calendar reform