diff --git a/classes/suggested-tasks/class-task.php b/classes/suggested-tasks/class-task.php
index c85db2fa6..b8f896e30 100644
--- a/classes/suggested-tasks/class-task.php
+++ b/classes/suggested-tasks/class-task.php
@@ -29,7 +29,7 @@
  * @property int|null $target_term_id The target term ID for the task
  * @property string|null $target_taxonomy The target taxonomy for the task
  * @property string|null $target_term_name The target term name for the task
- * @property string|null $date The task date in YW format (year-week)
+ * @property string|null $date The task date in oW format (ISO year + ISO week)
  */
 class Task {
 	/**
diff --git a/classes/suggested-tasks/class-tasks-manager.php b/classes/suggested-tasks/class-tasks-manager.php
index 880e5223e..64b2aefb5 100644
--- a/classes/suggested-tasks/class-tasks-manager.php
+++ b/classes/suggested-tasks/class-tasks-manager.php
@@ -315,7 +315,7 @@ public function cleanup_pending_tasks() {
 			$task_provider = $this->get_task_provider( $task->get_provider_id() );
 
 			// Should we delete the task? Delete tasks which don't have a task provider or repetitive tasks which were created in the previous week.
-			if ( ! $task_provider || ( $task_provider->is_repetitive() && ( ! $task->date || \gmdate( 'YW' ) !== (string) $task->date ) ) ) {
+			if ( ! $task_provider || ( $task_provider->is_repetitive() && ( ! $task->date || \gmdate( 'oW' ) !== (string) $task->date ) ) ) {
 				\progress_planner()->get_suggested_tasks_db()->delete_recommendation( $task->ID );
 			}
 		}
@@ -346,7 +346,7 @@ public function handle_task_unsnooze( $new_status, $old_status, $post ) {
 		$task_provider = $this->get_task_provider( $task->get_provider_id() );
 
 		// Delete tasks which don't have a task provider or repetitive tasks which were created in the previous week.
-		if ( ! $task_provider || ( $task_provider->is_repetitive() && ( ! $task->date || \gmdate( 'YW' ) !== (string) $task->date ) ) ) {
+		if ( ! $task_provider || ( $task_provider->is_repetitive() && ( ! $task->date || \gmdate( 'oW' ) !== (string) $task->date ) ) ) {
 			\progress_planner()->get_suggested_tasks_db()->delete_recommendation( $task->ID );
 		}
 
diff --git a/classes/suggested-tasks/providers/class-content-create.php b/classes/suggested-tasks/providers/class-content-create.php
index 4f038b0f6..94a72abbc 100644
--- a/classes/suggested-tasks/providers/class-content-create.php
+++ b/classes/suggested-tasks/providers/class-content-create.php
@@ -109,7 +109,7 @@ public function should_add_task() {
 		}
 
 		// Add tasks if there are no posts published this week.
-		return \gmdate( 'YW' ) !== \gmdate( 'YW', \strtotime( $last_published_post_data['post_date'] ) );
+		return \gmdate( 'oW' ) !== \gmdate( 'oW', \strtotime( $last_published_post_data['post_date'] ) );
 	}
 
 	/**
diff --git a/classes/suggested-tasks/providers/class-content-review.php b/classes/suggested-tasks/providers/class-content-review.php
index f0898f586..da23e6052 100644
--- a/classes/suggested-tasks/providers/class-content-review.php
+++ b/classes/suggested-tasks/providers/class-content-review.php
@@ -289,7 +289,7 @@ public function get_tasks_to_inject() {
 				'provider_id'       => $this->get_provider_id(),
 				'target_post_id'    => $task_data['target_post_id'],
 				'target_post_type'  => $task_data['target_post_type'],
-				'date'              => \gmdate( 'YW' ),
+				'date'              => \gmdate( 'oW' ),
 				'post_title'        => $this->get_title_with_data( $task_data ),
 				'url'               => $this->get_url_with_data( $task_data ),
 				'url_target'        => $this->get_url_target(),
diff --git a/classes/suggested-tasks/providers/class-tasks.php b/classes/suggested-tasks/providers/class-tasks.php
index eed1b097c..d074ed83a 100644
--- a/classes/suggested-tasks/providers/class-tasks.php
+++ b/classes/suggested-tasks/providers/class-tasks.php
@@ -295,7 +295,9 @@ public function get_task_id( $task_data = [] ) {
 		$parts[] = $task_data['target_taxonomy'] ?? false;
 		// If the task is repetitive, add the date as the last part (format: YYYYWW, e.g., 202542 for week 42 of 2025).
 		// This creates a new task instance each week for repetitive tasks.
-		$parts[] = $this->is_repetitive() ? \gmdate( 'YW' ) : false;
+		// Note: We use 'oW' format (ISO year + ISO week) instead of 'YW' to handle year boundaries correctly.
+		// For example, Dec 29, 2025 is ISO week 01 of 2026, so 'oW' returns '202601' while 'YW' would incorrectly return '202501'.
+		$parts[] = $this->is_repetitive() ? \gmdate( 'oW' ) : false;
 
 		// Remove empty parts to keep IDs clean.
 		$parts = \array_filter( $parts );
@@ -447,7 +449,7 @@ public function is_task_relevant() {
 	 * - Returns the task object if completed, false otherwise
 	 *
 	 * Repetitive tasks:
-	 * - Must be completed within the same week they were created (using YW format: year + week number)
+	 * - Must be completed within the same week they were created (using oW format: ISO year + ISO week number)
 	 * - For example, a task created in week 42 of 2025 must be completed in 2025W42
 	 * - This prevents tasks from previous weeks being marked as complete
 	 * - Allows child classes to add completion data (e.g., post_id for "create post" tasks)
@@ -483,8 +485,8 @@ public function evaluate_task( $task_id ) {
 			$task->provider &&
 			$task->provider->slug === $this->get_provider_id() &&
 			\DateTime::createFromFormat( 'Y-m-d H:i:s', $task->post_date ) &&
-			// Check if the task was created in the current week (YW format: e.g., 202542 = week 42 of 2025).
-			\gmdate( 'YW' ) === \gmdate( 'YW', \DateTime::createFromFormat( 'Y-m-d H:i:s', $task->post_date )->getTimestamp() ) && // @phpstan-ignore-line
+			// Check if the task was created in the current week (oW format: ISO year + ISO week, e.g., 202542 = week 42 of 2025).
+			\gmdate( 'oW' ) === \gmdate( 'oW', \DateTime::createFromFormat( 'Y-m-d H:i:s', $task->post_date )->getTimestamp() ) && // @phpstan-ignore-line
 			$this->is_task_completed( \progress_planner()->get_suggested_tasks()->get_task_id_from_slug( $task->post_name ) )
 		) {
 			// Allow adding more data, for example in case of 'create-post' tasks we are adding the post_id.
@@ -599,7 +601,7 @@ public function get_task_details( $task_data = [] ) {
 			'parent'            => $this->get_parent(),
 			'priority'          => $this->get_priority(),
 			'points'            => $this->get_points(),
-			'date'              => \gmdate( 'YW' ),
+			'date'              => \gmdate( 'oW' ),
 			'url'               => $this->get_url_with_data( $task_data ),
 			'url_target'        => $this->get_url_target(),
 			'link_setting'      => $this->get_link_setting(),
diff --git a/classes/suggested-tasks/providers/traits/class-dismissable-task.php b/classes/suggested-tasks/providers/traits/class-dismissable-task.php
index 15a07f63f..5c068538d 100644
--- a/classes/suggested-tasks/providers/traits/class-dismissable-task.php
+++ b/classes/suggested-tasks/providers/traits/class-dismissable-task.php
@@ -87,7 +87,7 @@ public function handle_task_dismissal( $post_id ) {
 
 		// Store the task dismissal data.
 		$dismissal_data = [
-			'date'      => \gmdate( 'YW' ),
+			'date'      => \gmdate( 'oW' ),
 			'timestamp' => \time(),
 		];
 
@@ -157,7 +157,7 @@ protected function is_task_dismissed( $task_data ) {
 		$dismissal_data = $dismissed_tasks[ $provider_key ][ $task_identifier ];
 
 		// If the task was dismissed in the current week, don't show it again.
-		if ( $dismissal_data['date'] === \gmdate( 'YW' ) ) {
+		if ( $dismissal_data['date'] === \gmdate( 'oW' ) ) {
 			return true;
 		}
 
diff --git a/tests/phpunit/test-class-suggested-tasks.php b/tests/phpunit/test-class-suggested-tasks.php
index a13eef01d..fec2a15d4 100644
--- a/tests/phpunit/test-class-suggested-tasks.php
+++ b/tests/phpunit/test-class-suggested-tasks.php
@@ -21,30 +21,30 @@ public function test_task_cleanup() {
 		// Tasks that should not be removed.
 		$tasks_to_keep = [
 			[
-				'post_title'  => 'review-post-14-' . \gmdate( 'YW' ),
-				'task_id'     => 'review-post-14-' . \gmdate( 'YW' ),
-				'date'        => \gmdate( 'YW' ),
+				'post_title'  => 'review-post-14-' . \gmdate( 'oW' ),
+				'task_id'     => 'review-post-14-' . \gmdate( 'oW' ),
+				'date'        => \gmdate( 'oW' ),
 				'category'    => 'content-update',
 				'provider_id' => 'review-post',
 			],
 			[
-				'post_title'  => 'create-post-' . \gmdate( 'YW' ),
-				'task_id'     => 'create-post-' . \gmdate( 'YW' ),
-				'date'        => \gmdate( 'YW' ),
+				'post_title'  => 'create-post-' . \gmdate( 'oW' ),
+				'task_id'     => 'create-post-' . \gmdate( 'oW' ),
+				'date'        => \gmdate( 'oW' ),
 				'category'    => 'content-new',
 				'provider_id' => 'create-post',
 			],
 			[
-				'post_title'  => 'update-core-' . \gmdate( 'YW' ),
-				'task_id'     => 'update-core-' . \gmdate( 'YW' ),
-				'date'        => \gmdate( 'YW' ),
+				'post_title'  => 'update-core-' . \gmdate( 'oW' ),
+				'task_id'     => 'update-core-' . \gmdate( 'oW' ),
+				'date'        => \gmdate( 'oW' ),
 				'category'    => 'maintenance',
 				'provider_id' => 'update-core',
 			],
 			[
-				'post_title'  => 'core-siteicon-' . \gmdate( 'YW' ),
-				'task_id'     => 'core-siteicon-' . \gmdate( 'YW' ),
-				'date'        => \gmdate( 'YW' ),
+				'post_title'  => 'core-siteicon-' . \gmdate( 'oW' ),
+				'task_id'     => 'core-siteicon-' . \gmdate( 'oW' ),
+				'date'        => \gmdate( 'oW' ),
 				'provider_id' => 'core-siteicon',
 				'category'    => 'configuration',
 			],