diff --git a/src/Repository/CardRepository.php b/src/Repository/CardRepository.php
index 3b6414f..8576d39 100644
--- a/src/Repository/CardRepository.php
+++ b/src/Repository/CardRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Repository;
 
+use App\Support\Database;
 use PDO;
 
 /**
@@ -112,7 +113,7 @@ final class CardRepository
      */
     public function update(int $id, array $fields): array
     {
-        $sets = ['updated_at = ' . $this->nowExpr()];
+        $sets = ['updated_at = ' . Database::nowExpr()];
         $params = ['id' => $id];
 
         if (array_key_exists('text', $fields)) {
@@ -185,7 +186,7 @@ final class CardRepository
 
             $place = $this->pdo->prepare(
                 'UPDATE cards SET project_id = :project, status_id = :status, position = :position,
-                        updated_at = ' . $this->nowExpr() . '
+                        updated_at = ' . Database::nowExpr() . '
                  WHERE id = :id AND owner_id = :owner'
             );
             foreach ($orderedIds as $position => $id) {
@@ -229,7 +230,7 @@ final class CardRepository
 
         $next = $this->nextPositionInColumn($ownerId, $projectId, $toStatusId);
         $stmt = $this->pdo->prepare(
-            'UPDATE cards SET status_id = :status, position = :position, updated_at = ' . $this->nowExpr() . '
+            'UPDATE cards SET status_id = :status, position = :position, updated_at = ' . Database::nowExpr() . '
              WHERE id = :id AND owner_id = :owner'
         );
         foreach ($ids as $i => $id) {
@@ -362,11 +363,6 @@ final class CardRepository
         return $row === false ? null : $this->cast($row);
     }
 
-    private function nowExpr(): string
-    {
-        return "strftime('%Y-%m-%dT%H:%M:%SZ', 'now')";
-    }
-
     /**
      * @param array<string, mixed> $row
      * @return CardRow
diff --git a/src/Repository/CardStatusRepository.php b/src/Repository/CardStatusRepository.php
index 647ab7a..38e411e 100644
--- a/src/Repository/CardStatusRepository.php
+++ b/src/Repository/CardStatusRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Repository;
 
+use App\Support\Database;
 use PDO;
 
 /**
@@ -100,7 +101,7 @@ final class CardStatusRepository
     public function reorder(int $projectId, array $orderedIds): array
     {
         $stmt = $this->pdo->prepare(
-            'UPDATE card_statuses SET position = :position, updated_at = ' . $this->nowExpr() . '
+            'UPDATE card_statuses SET position = :position, updated_at = ' . Database::nowExpr() . '
              WHERE id = :id AND project_id = :project'
         );
         foreach (array_values($orderedIds) as $position => $id) {
@@ -160,11 +161,6 @@ final class CardStatusRepository
         return $row === false ? null : $this->cast($row);
     }
 
-    private function nowExpr(): string
-    {
-        return "strftime('%Y-%m-%dT%H:%M:%SZ', 'now')";
-    }
-
     /**
      * @param array<string, mixed> $row
      * @return CardStatusRow
diff --git a/src/Repository/EmailVerificationRepository.php b/src/Repository/EmailVerificationRepository.php
index fcf520d..b3fc4d0 100644
--- a/src/Repository/EmailVerificationRepository.php
+++ b/src/Repository/EmailVerificationRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Repository;
 
+use App\Support\Database;
 use PDO;
 
 /**
@@ -70,8 +71,8 @@ final class EmailVerificationRepository
     public function consume(int $id): bool
     {
         $stmt = $this->pdo->prepare(
-            "UPDATE email_verifications SET consumed_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
-             WHERE id = :id AND consumed_at IS NULL"
+            'UPDATE email_verifications SET consumed_at = ' . Database::nowExpr() . '
+             WHERE id = :id AND consumed_at IS NULL'
         );
         $stmt->execute(['id' => $id]);
 
@@ -84,10 +85,10 @@ final class EmailVerificationRepository
     public function pendingEmailFor(int $userId): ?string
     {
         $stmt = $this->pdo->prepare(
-            "SELECT new_email FROM email_verifications
+            'SELECT new_email FROM email_verifications
              WHERE user_id = :user AND new_email IS NOT NULL AND consumed_at IS NULL
-               AND expires_at > strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
-             ORDER BY id DESC LIMIT 1"
+               AND expires_at > ' . Database::nowExpr() . '
+             ORDER BY id DESC LIMIT 1'
         );
         $stmt->execute(['user' => $userId]);
 
diff --git a/src/Repository/PasskeyRepository.php b/src/Repository/PasskeyRepository.php
index dff4b11..35d4963 100644
--- a/src/Repository/PasskeyRepository.php
+++ b/src/Repository/PasskeyRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Repository;
 
+use App\Support\Database;
 use PDO;
 
 /**
@@ -94,8 +95,8 @@ final class PasskeyRepository
     public function markUsed(int $id, int $signCount): void
     {
         $this->pdo->prepare(
-            "UPDATE passkeys SET sign_count = :count, last_used_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
-             WHERE id = :id"
+            'UPDATE passkeys SET sign_count = :count, last_used_at = ' . Database::nowExpr() . '
+             WHERE id = :id'
         )->execute(['count' => $signCount, 'id' => $id]);
     }
 
diff --git a/src/Repository/ProjectRepository.php b/src/Repository/ProjectRepository.php
index 60b3d28..ffce5a7 100644
--- a/src/Repository/ProjectRepository.php
+++ b/src/Repository/ProjectRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Repository;
 
+use App\Support\Database;
 use PDO;
 
 /**
@@ -90,7 +91,7 @@ final class ProjectRepository
      */
     public function update(int $id, int $ownerId, array $fields): array
     {
-        $sets = ['updated_at = ' . $this->nowExpr()];
+        $sets = ['updated_at = ' . Database::nowExpr()];
         $params = ['id' => $id];
 
         foreach (['title', 'description'] as $column) {
@@ -117,15 +118,10 @@ final class ProjectRepository
     /** Bump updated_at, e.g. when the project's cards change. */
     public function touch(int $id): void
     {
-        $this->pdo->prepare('UPDATE projects SET updated_at = ' . $this->nowExpr() . ' WHERE id = :id')
+        $this->pdo->prepare('UPDATE projects SET updated_at = ' . Database::nowExpr() . ' WHERE id = :id')
             ->execute(['id' => $id]);
     }
 
-    private function nowExpr(): string
-    {
-        return "strftime('%Y-%m-%dT%H:%M:%SZ', 'now')";
-    }
-
     /**
      * @param array<string, mixed> $row
      * @return ProjectRow
diff --git a/src/Repository/UserRepository.php b/src/Repository/UserRepository.php
index bd6192d..7df2646 100644
--- a/src/Repository/UserRepository.php
+++ b/src/Repository/UserRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Repository;
 
+use App\Support\Database;
 use PDO;
 use PDOException;
 
@@ -88,10 +89,9 @@ final class UserRepository
 
     public function markEmailVerified(int $id): void
     {
+        $now = Database::nowExpr();
         $this->pdo->prepare(
-            "UPDATE users SET email_verified_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now'),
-                    updated_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
-             WHERE id = :id"
+            "UPDATE users SET email_verified_at = {$now}, updated_at = {$now} WHERE id = :id"
         )->execute(['id' => $id]);
     }
 
@@ -100,18 +100,16 @@ final class UserRepository
      */
     public function updateEmail(int $id, string $email): void
     {
+        $now = Database::nowExpr();
         $this->pdo->prepare(
-            "UPDATE users SET email = :email,
-                    email_verified_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now'),
-                    updated_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
-             WHERE id = :id"
+            "UPDATE users SET email = :email, email_verified_at = {$now}, updated_at = {$now} WHERE id = :id"
         )->execute(['email' => $email, 'id' => $id]);
     }
 
     public function markVerificationEmailSent(int $id): void
     {
         $this->pdo->prepare(
-            "UPDATE users SET verification_email_sent_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now') WHERE id = :id"
+            'UPDATE users SET verification_email_sent_at = ' . Database::nowExpr() . ' WHERE id = :id'
         )->execute(['id' => $id]);
     }
 
diff --git a/src/Repository/WebAuthnChallengeRepository.php b/src/Repository/WebAuthnChallengeRepository.php
index eac9595..94dbd27 100644
--- a/src/Repository/WebAuthnChallengeRepository.php
+++ b/src/Repository/WebAuthnChallengeRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Repository;
 
+use App\Support\Database;
 use PDO;
 
 /**
@@ -66,8 +67,8 @@ final class WebAuthnChallengeRepository
         }
 
         $update = $this->pdo->prepare(
-            "UPDATE webauthn_challenges SET consumed_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
-             WHERE id = :id AND consumed_at IS NULL"
+            'UPDATE webauthn_challenges SET consumed_at = ' . Database::nowExpr() . '
+             WHERE id = :id AND consumed_at IS NULL'
         );
         $update->execute(['id' => $id]);
 
diff --git a/src/Support/Database.php b/src/Support/Database.php
index cca1624..5638fd6 100644
--- a/src/Support/Database.php
+++ b/src/Support/Database.php
@@ -29,4 +29,14 @@ final class Database
     {
         return $this->pdo;
     }
+
+    /**
+     * SQL expression for the current UTC time, in the format every
+     * created_at/updated_at/*_at column uses (both as their DEFAULT in the
+     * migrations and wherever a repository sets one explicitly).
+     */
+    public static function nowExpr(): string
+    {
+        return "strftime('%Y-%m-%dT%H:%M:%SZ', 'now')";
+    }
 }