1 files changed, 29 insertions, 2 deletions
diff --git a/spec/ruby/core/time/iso8601_spec.rb b/spec/ruby/core/time/iso8601_spec.rb
index ad60c3bb32..a6efc57b28 100644
--- a/spec/ruby/core/time/iso8601_spec.rb
+++ b/spec/ruby/core/time/iso8601_spec.rb
@@ -1,6 +1,33 @@
 require_relative '../../spec_helper'
-require_relative 'shared/xmlschema'
 
 describe "Time#iso8601" do
-  it_behaves_like :time_xmlschema, :iso8601
+  ruby_version_is "3.4" do
+    it "generates ISO-8601 strings in Z for UTC times" do
+      t = Time.utc(1985, 4, 12, 23, 20, 50, 521245)
+      t.iso8601.should == "1985-04-12T23:20:50Z"
+      t.iso8601(2).should == "1985-04-12T23:20:50.52Z"
+      t.iso8601(9).should == "1985-04-12T23:20:50.521245000Z"
+    end
+
+    it "generates ISO-8601 string with timezone offset for non-UTC times" do
+      t = Time.new(1985, 4, 12, 23, 20, 50, "+02:00")
+      t.iso8601.should == "1985-04-12T23:20:50+02:00"
+      t.iso8601(2).should == "1985-04-12T23:20:50.00+02:00"
+    end
+
+    it "year is always at least 4 digits" do
+      t = Time.utc(12, 4, 12)
+      t.iso8601.should ==  "0012-04-12T00:00:00Z"
+    end
+
+    it "year can be more than 4 digits" do
+      t = Time.utc(40_000, 4, 12)
+      t.iso8601.should ==  "40000-04-12T00:00:00Z"
+    end
+
+    it "year can be negative" do
+      t = Time.utc(-2000, 4, 12)
+      t.iso8601.should ==  "-2000-04-12T00:00:00Z"
+    end
+  end
 end