diff --git a/test/date_test/day.pass.cpp b/test/date_test/day.pass.cpp
index 124f814..0dbdf68 100644
--- a/test/date_test/day.pass.cpp
+++ b/test/date_test/day.pass.cpp
@@ -60,7 +60,7 @@
 #include <type_traits>
 
 static_assert( std::is_trivially_destructible<date::day>{}, "");
-static_assert(!std::is_default_constructible<date::day>{}, "");
+static_assert( std::is_default_constructible<date::day>{}, "");
 static_assert( std::is_trivially_copy_constructible<date::day>{}, "");
 static_assert( std::is_trivially_copy_assignable<date::day>{}, "");
 static_assert( std::is_trivially_move_constructible<date::day>{}, "");
diff --git a/test/date_test/month.pass.cpp b/test/date_test/month.pass.cpp
index 1621d95..4dffa6b 100644
--- a/test/date_test/month.pass.cpp
+++ b/test/date_test/month.pass.cpp
@@ -72,7 +72,7 @@
 #include <type_traits>
 
 static_assert( std::is_trivially_destructible<date::month>{}, "");
-static_assert(!std::is_default_constructible<date::month>{}, "");
+static_assert( std::is_default_constructible<date::month>{}, "");
 static_assert( std::is_trivially_copy_constructible<date::month>{}, "");
 static_assert( std::is_trivially_copy_assignable<date::month>{}, "");
 static_assert( std::is_trivially_move_constructible<date::month>{}, "");
diff --git a/test/date_test/month_day.pass.cpp b/test/date_test/month_day.pass.cpp
index 39dd66c..5fca9b2 100644
--- a/test/date_test/month_day.pass.cpp
+++ b/test/date_test/month_day.pass.cpp
@@ -47,7 +47,7 @@
 #include <type_traits>
 
 static_assert( std::is_trivially_destructible<date::month_day>{}, "");
-static_assert(!std::is_default_constructible<date::month_day>{}, "");
+static_assert( std::is_default_constructible<date::month_day>{}, "");
 static_assert( std::is_trivially_copy_constructible<date::month_day>{}, "");
 static_assert( std::is_trivially_copy_assignable<date::month_day>{}, "");
 static_assert( std::is_trivially_move_constructible<date::month_day>{}, "");
diff --git a/test/date_test/weekday.pass.cpp b/test/date_test/weekday.pass.cpp
index fe0c183..1a526d0 100644
--- a/test/date_test/weekday.pass.cpp
+++ b/test/date_test/weekday.pass.cpp
@@ -69,7 +69,7 @@
 #include <type_traits>
 
 static_assert( std::is_trivially_destructible<date::weekday>{}, "");
-static_assert(!std::is_default_constructible<date::weekday>{}, "");
+static_assert( std::is_default_constructible<date::weekday>{}, "");
 static_assert( std::is_trivially_copy_constructible<date::weekday>{}, "");
 static_assert( std::is_trivially_copy_assignable<date::weekday>{}, "");
 static_assert( std::is_trivially_move_constructible<date::weekday>{}, "");
diff --git a/test/date_test/year.pass.cpp b/test/date_test/year.pass.cpp
index 2c0044c..27d9df6 100644
--- a/test/date_test/year.pass.cpp
+++ b/test/date_test/year.pass.cpp
@@ -64,7 +64,7 @@
 #include <type_traits>
 
 static_assert( std::is_trivially_destructible<date::year>{}, "");
-static_assert(!std::is_default_constructible<date::year>{}, "");
+static_assert( std::is_default_constructible<date::year>{}, "");
 static_assert( std::is_trivially_copy_constructible<date::year>{}, "");
 static_assert( std::is_trivially_copy_assignable<date::year>{}, "");
 static_assert( std::is_trivially_move_constructible<date::year>{}, "");
diff --git a/test/date_test/year_month.pass.cpp b/test/date_test/year_month.pass.cpp
index 191e8b0..2f00541 100644
--- a/test/date_test/year_month.pass.cpp
+++ b/test/date_test/year_month.pass.cpp
@@ -61,7 +61,7 @@
 #include <type_traits>
 
 static_assert( std::is_trivially_destructible<date::year_month>{}, "");
-static_assert(!std::is_default_constructible<date::year_month>{}, "");
+static_assert( std::is_default_constructible<date::year_month>{}, "");
 static_assert( std::is_trivially_copy_constructible<date::year_month>{}, "");
 static_assert( std::is_trivially_copy_assignable<date::year_month>{}, "");
 static_assert( std::is_trivially_move_constructible<date::year_month>{}, "");
diff --git a/test/date_test/year_month_day.pass.cpp b/test/date_test/year_month_day.pass.cpp
index cea75d0..9166888 100644
--- a/test/date_test/year_month_day.pass.cpp
+++ b/test/date_test/year_month_day.pass.cpp
@@ -64,7 +64,7 @@
 #include <type_traits>
 
 static_assert( std::is_trivially_destructible<date::year_month_day>{}, "");
-static_assert(!std::is_default_constructible<date::year_month_day>{}, "");
+static_assert( std::is_default_constructible<date::year_month_day>{}, "");
 static_assert( std::is_trivially_copy_constructible<date::year_month_day>{}, "");
 static_assert( std::is_trivially_copy_assignable<date::year_month_day>{}, "");
 static_assert( std::is_trivially_move_constructible<date::year_month_day>{}, "");