12 files changed, 12 insertions, 0 deletions
diff --git a/test/date/test_date.rb b/test/date/test_date.rb
index 3d8bf868c4..3bb1f4a4c7 100644
--- a/test/date/test_date.rb
+++ b/test/date/test_date.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_arith.rb b/test/date/test_date_arith.rb
index 7b79c18097..f5ac5bf30b 100644
--- a/test/date/test_date_arith.rb
+++ b/test/date/test_date_arith.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_attr.rb b/test/date/test_date_attr.rb
index bc6bec2a80..3d1b0a2e6e 100644
--- a/test/date/test_date_attr.rb
+++ b/test/date/test_date_attr.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_base.rb b/test/date/test_date_base.rb
index 1f3d8c0a55..06fec19e52 100644
--- a/test/date/test_date_base.rb
+++ b/test/date/test_date_base.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_compat.rb b/test/date/test_date_compat.rb
index 8284007407..1bd30b5f80 100644
--- a/test/date/test_date_compat.rb
+++ b/test/date/test_date_compat.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_conv.rb b/test/date/test_date_conv.rb
index daf0374294..8b99970dd7 100644
--- a/test/date/test_date_conv.rb
+++ b/test/date/test_date_conv.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_marshal.rb b/test/date/test_date_marshal.rb
index 4ea5565716..27ae1e9004 100644
--- a/test/date/test_date_marshal.rb
+++ b/test/date/test_date_marshal.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_new.rb b/test/date/test_date_new.rb
index 0bbbfee44b..80ecbc204e 100644
--- a/test/date/test_date_new.rb
+++ b/test/date/test_date_new.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_parse.rb b/test/date/test_date_parse.rb
index e0cd6025a8..d980674591 100644
--- a/test/date/test_date_parse.rb
+++ b/test/date/test_date_parse.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_strftime.rb b/test/date/test_date_strftime.rb
index 0ed9215e1e..7472a4323d 100644
--- a/test/date/test_date_strftime.rb
+++ b/test/date/test_date_strftime.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_date_strptime.rb b/test/date/test_date_strptime.rb
index ae149bb8d8..15fdc949f5 100644
--- a/test/date/test_date_strptime.rb
+++ b/test/date/test_date_strptime.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'
 
diff --git a/test/date/test_switch_hitter.rb b/test/date/test_switch_hitter.rb
index 08e23015dc..931d736edf 100644
--- a/test/date/test_switch_hitter.rb
+++ b/test/date/test_switch_hitter.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'test/unit'
 require 'date'