diff --git a/core/time/new_spec.rb b/core/time/new_spec.rb
index 69ec7bee5..6dce5b73f 100644
--- a/core/time/new_spec.rb
+++ b/core/time/new_spec.rb
@@ -475,4 +475,94 @@ def zone.local_to_utc(t)
       end
     end
   end
+
+  ruby_version_is "3.2" do
+    it "parses a time string" do
+      t = Time.utc(2020, 12, 24, 15, 56, 17)
+
+      Time.new("2020-12-24T15:56:17Z").should == t
+      Time.new("2020-12-25 00:56:17 +09:00").should == t
+      Time.new("2020-12-25 00:57:47 +09:01:30").should == t
+      Time.new("2020-12-25 00:56:17 +0900").should == t
+      Time.new("2020-12-25 00:57:47 +090130").should == t
+      Time.new("2020-12-25T00:56:17+09:00").should == t
+    end
+
+    it "accepts precission keyword argument" do
+      Time.new("2021-12-25 00:00:00.123456789876 +09:00", precision: 3).subsec.should == 0.123r
+      Time.new("2021-12-25 00:00:00.123456789876 +09:00", precision: nil).subsec.should == 0.123456789876r
+    end
+
+    it "raises ArgumentError if part of time string is missing" do
+      -> {
+        Time.new("2020-12-25 00:56 +09:00")
+      }.should raise_error(ArgumentError, /missing sec part/)
+
+      -> {
+        Time.new("2020-12-25 00 +09:00")
+      }.should raise_error(ArgumentError, /missing min part/)
+    end
+
+    it "raises ArgumentError if zone argument is passed without in: keyword" do
+      -> {
+        Time.new(2021, 1, 1, "+09:99")
+      }.should raise_error(ArgumentError, /invalid value for Integer()/)
+    end
+
+    it "raises ArgumentError if subsecond is missing after dot" do
+      -> {
+        Time.new("2020-12-25 00:56:17. +0900")
+      }.should raise_error(ArgumentError, "subsecond expected after dot: 00:56:17. ")
+    end
+
+    it "raises ArgumentError if string argument is not valid" do
+      -> {
+        Time.new("021-12-25 00:00:00.123456 +09:00")
+      }.should raise_error(ArgumentError, /year must be 4 or more/)
+
+      -> {
+        Time.new("2020-012-25 00:56:17 +0900")
+      }.should raise_error(ArgumentError, /two digits mon.*\b012\b/)
+
+      -> {
+        Time.new("2020-2-25 00:56:17 +0900")
+      }.should raise_error(ArgumentError, /two digits mon.*\b2\b/)
+
+      -> {
+        Time.new("2020-12-215 00:56:17 +0900")
+      }.should raise_error(ArgumentError, /two digits mday.*\b215\b/)
+
+      -> {
+        Time.new("2020-12-25 000:56:17 +0900")
+      }.should raise_error(ArgumentError, /two digits hour.*\b000\b/)
+
+      -> {
+        Time.new("2020-12-25 0:56:17 +0900")
+      }.should raise_error(ArgumentError, /two digits hour.*\b0\b/)
+
+      -> {
+        Time.new("2020-12-25 00:516:17 +0900")
+      }.should raise_error(ArgumentError, /two digits min.*:516\b/)
+
+      -> {
+        Time.new("2020-12-25 00:6:17 +0900")
+      }.should raise_error(ArgumentError, /two digits min.*:6\b/)
+
+      -> {
+        Time.new("2020-12-25 00:56:137 +0900")
+      }.should raise_error(ArgumentError, /two digits sec.*:137\b/)
+
+      -> {
+        Time.new("2020-12-25 00:56:7 +0900")
+      }.should raise_error(ArgumentError, /two digits sec.*:7\b/)
+
+      -> {
+        Time.new("2020-12-25 00:56. +0900")
+      }.should raise_error(ArgumentError, /fraction min is.*56\./)
+
+      -> {
+        Time.new("2020-12-25 00. +0900")
+      }.should raise_error(ArgumentError, /fraction hour is.*00\./)
+    end
+  end
 end