diff --git a/lib/time.rb b/lib/time.rb
index d945e876ae..e227166c47 100644
--- a/lib/time.rb
+++ b/lib/time.rb
@@ -571,7 +571,7 @@ class Time
           T
           (\d\d):(\d\d):(\d\d)
           (\.\d+)?
-          (Z|[+-]\d\d:?\d\d)?
+          (Z|[+-]\d\d(?::?\d\d)?)?
           \s*\z/ix =~ date
         year = $1.to_i
         mon = $2.to_i
diff --git a/test/test_time.rb b/test/test_time.rb
index d01d74eb52..26a7daaf2a 100644
--- a/test/test_time.rb
+++ b/test/test_time.rb
@@ -106,6 +106,7 @@ class TestTimeExtension < Test::Unit::TestCase # :nodoc:
     s = "1996-12-19T16:39:57-08:00"
     assert_equal(t, Time.__send__(method, s))
     assert_equal(t, Time.__send__(method, s.sub(/:(?=00\z)/, '')))
+    assert_equal(t, Time.__send__(method, s.sub(/:00\z/, '')))
     # There is no way to generate time string with arbitrary timezone.
     s = "1996-12-20T00:39:57Z"
     assert_equal(t, Time.__send__(method, s))