diff --git a/CHANGELOG.md b/CHANGELOG.md
index 486381b..8c7f9f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ Changed
 - Trait `ManagesStaleReads` has been removed (which contained `cursorWithTimestampBound()` and `selectWithTimestampBound()`. Use `selectWithOptions()` instead). (#178)
 - `Blueprint::interleave()` and `IndexDefinition::interleave()` now throw an error instead of a deprecation. (#178)
 - `Connection::transaction()`'s `$attempts` argument's default value was changed from 10 to -1 (which is a magic number for default value which is 11) (#179)
+- All upper case functions and casting `DATE` `TIMESTAMP` `CURRENT_TIMESTAMP()` has been changed to lower case for consistency. (#182)
 
 Fixed
 - `Schema\Grammar::compileAdd()` `Schema\Grammar::compileChange()` `Schema\Grammar::compileChange()` now create separate statements (#159)
diff --git a/src/Schema/Grammar.php b/src/Schema/Grammar.php
index 2e7e31d..8017253 100644
--- a/src/Schema/Grammar.php
+++ b/src/Schema/Grammar.php
@@ -591,7 +591,7 @@ protected function typeDateTime(Fluent $column)
     protected function typeTimestamp(Fluent $column)
     {
         if ($column->useCurrent) {
-            $column->default(new Expression('CURRENT_TIMESTAMP()'));
+            $column->default(new Expression('current_timestamp()'));
         }
 
         return 'timestamp';
@@ -736,7 +736,7 @@ protected function formatDateValue(Fluent $column, mixed $value): string
         if (is_string($value)) {
             $value = Carbon::parse($value);
         }
-        return 'DATE "' . $value->format('Y-m-d') . '"';
+        return 'date "' . $value->format('Y-m-d') . '"';
     }
 
     /**
@@ -794,7 +794,7 @@ protected function formatTimestampValue(Fluent $column, mixed $value): string
         if (is_string($value)) {
             $value = Carbon::parse($value);
         }
-        return 'TIMESTAMP "' . $value->format($this->getDateFormat()) . '"';
+        return 'timestamp "' . $value->format($this->getDateFormat()) . '"';
     }
 
     /**
diff --git a/tests/Schema/BlueprintTest.php b/tests/Schema/BlueprintTest.php
index 338e8c7..f0aff91 100644
--- a/tests/Schema/BlueprintTest.php
+++ b/tests/Schema/BlueprintTest.php
@@ -23,7 +23,6 @@
 use Illuminate\Support\Carbon;
 use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Str;
-use LogicException;
 use Ramsey\Uuid\Uuid;
 
 class BlueprintTest extends TestCase
@@ -442,18 +441,18 @@ public function test_default_values(): void
                 '`long_text` string(max) not null default ("a")',
                 '`raw` float64 not null default (1.1)',
                 '`json` json not null default (json "[1,2,3]")',
-                '`date_as_string` date not null default (DATE "2022-01-01")',
-                '`date_as_carbon` date not null default (DATE "2022-01-01")',
-                '`time_as_string` timestamp not null default (TIMESTAMP "2022-01-01T00:00:00.000000+00:00")',
-                '`time_as_carbon` timestamp not null default (TIMESTAMP "2022-01-01T00:00:00.000000+00:00")',
-                '`current_time` timestamp not null default (CURRENT_TIMESTAMP())',
-                '`current_time_as_ts` timestamp not null default (CURRENT_TIMESTAMP())',
+                '`date_as_string` date not null default (date "2022-01-01")',
+                '`date_as_carbon` date not null default (date "2022-01-01")',
+                '`time_as_string` timestamp not null default (timestamp "2022-01-01T00:00:00.000000+00:00")',
+                '`time_as_carbon` timestamp not null default (timestamp "2022-01-01T00:00:00.000000+00:00")',
+                '`current_time` timestamp not null default (current_timestamp())',
+                '`current_time_as_ts` timestamp not null default (current_timestamp())',
                 '`int_array` array<int64> not null default ([1, 2])',
                 '`bool_array` array<bool> not null default ([false, true])',
                 '`float_array` array<float64> not null default ([2.2, 3.3])',
                 '`string_array` array<string(1)> not null default (["a", "b"])',
-                '`date_array` array<date> not null default ([DATE "2022-01-01"])',
-                '`timestamp_array` array<timestamp> not null default ([TIMESTAMP "2022-01-01T00:00:00.000000+00:00"])',
+                '`date_array` array<date> not null default ([date "2022-01-01"])',
+                '`timestamp_array` array<timestamp> not null default ([timestamp "2022-01-01T00:00:00.000000+00:00"])',
             ]) . ') primary key (`id`)',
         ], $statements);
 
diff --git a/tests/TestCase.php b/tests/TestCase.php
index 64f1434..7bb4434 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -21,6 +21,7 @@
 use Colopl\Spanner\Connection;
 use Colopl\Spanner\Schema\Blueprint;
 use Colopl\Spanner\SpannerServiceProvider;
+use DateTimeImmutable;
 use Google\Cloud\Spanner\Bytes;
 use Google\Cloud\Spanner\Date;
 use Google\Cloud\Spanner\Numeric;
@@ -85,9 +86,9 @@ protected function generateTestRow(): array
             'nullableFloatTest' => null,
             'numericTest' => new Numeric('123.456'),
             'nullableNumericTest' => null,
-            'timestampTest' => new \DateTimeImmutable(),
+            'timestampTest' => new DateTimeImmutable(),
             'nullableTimestampTest' => null,
-            'dateTest' => new Date(new \DateTimeImmutable()),
+            'dateTest' => new Date(new DateTimeImmutable()),
             'nullableDateTest' => null,
             'bytesTest' => new Bytes("\x00\x01\x02"),
             'nullableBytesTest' => null,