diff --git a/src/wp-includes/class-wp-comment-query.php b/src/wp-includes/class-wp-comment-query.php
index 195b96bb00..f6a17d7687 100644
--- a/src/wp-includes/class-wp-comment-query.php
+++ b/src/wp-includes/class-wp-comment-query.php
@@ -393,11 +393,8 @@ class WP_Comment_Query {
 
 		// $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
 		$key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
-		$last_changed = wp_cache_get( 'last_changed', 'comment' );
-		if ( ! $last_changed ) {
-			$last_changed = microtime();
-			wp_cache_set( 'last_changed', $last_changed, 'comment' );
-		}
+		$last_changed = wp_cache_get_last_changed( 'comment' );
+
 
 		$cache_key   = "get_comments:$key:$last_changed";
 		$cache_value = wp_cache_get( $cache_key, 'comment' );
@@ -972,11 +969,7 @@ class WP_Comment_Query {
 		}
 
 		$key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
-		$last_changed = wp_cache_get( 'last_changed', 'comment' );
-		if ( ! $last_changed ) {
-			$last_changed = microtime();
-			wp_cache_set( 'last_changed', $last_changed, 'comment' );
-		}
+		$last_changed = wp_cache_get_last_changed( 'comment' );
 
 		// Fetch an entire level of the descendant tree at a time.
 		$level = 0;
diff --git a/src/wp-includes/class-wp-network-query.php b/src/wp-includes/class-wp-network-query.php
index ffff041c4d..1bf38ad7e2 100644
--- a/src/wp-includes/class-wp-network-query.php
+++ b/src/wp-includes/class-wp-network-query.php
@@ -209,11 +209,7 @@ class WP_Network_Query {
 
 		// $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
 		$key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
-		$last_changed = wp_cache_get( 'last_changed', 'networks' );
-		if ( ! $last_changed ) {
-			$last_changed = microtime();
-			wp_cache_set( 'last_changed', $last_changed, 'networks' );
-		}
+		$last_changed = wp_cache_get_last_changed( 'networks' );
 
 		$cache_key = "get_network_ids:$key:$last_changed";
 		$cache_value = wp_cache_get( $cache_key, 'networks' );
diff --git a/src/wp-includes/class-wp-site-query.php b/src/wp-includes/class-wp-site-query.php
index 3ef9a38f7e..8f52372d3b 100644
--- a/src/wp-includes/class-wp-site-query.php
+++ b/src/wp-includes/class-wp-site-query.php
@@ -245,11 +245,7 @@ class WP_Site_Query {
 
 		// $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
 		$key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
-		$last_changed = wp_cache_get( 'last_changed', 'sites' );
-		if ( ! $last_changed ) {
-			$last_changed = microtime();
-			wp_cache_set( 'last_changed', $last_changed, 'sites' );
-		}
+		$last_changed = wp_cache_get_last_changed( 'sites' );
 
 		$cache_key = "get_sites:$key:$last_changed";
 		$cache_value = wp_cache_get( $cache_key, 'sites' );
diff --git a/src/wp-includes/class-wp-term-query.php b/src/wp-includes/class-wp-term-query.php
index f0df73f906..64b5578543 100644
--- a/src/wp-includes/class-wp-term-query.php
+++ b/src/wp-includes/class-wp-term-query.php
@@ -673,11 +673,7 @@ class WP_Term_Query {
 
 		// $args can be anything. Only use the args defined in defaults to compute the key.
 		$key = md5( serialize( wp_array_slice_assoc( $args, array_keys( $this->query_var_defaults ) ) ) . serialize( $taxonomies ) . $this->request );
-		$last_changed = wp_cache_get( 'last_changed', 'terms' );
-		if ( ! $last_changed ) {
-			$last_changed = microtime();
-			wp_cache_set( 'last_changed', $last_changed, 'terms' );
-		}
+		$last_changed = wp_cache_get_last_changed( 'terms' );
 		$cache_key = "get_terms:$key:$last_changed";
 		$cache = wp_cache_get( $cache_key, 'terms' );
 		if ( false !== $cache ) {
diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 1c86dc37ca..fb732e6590 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -5553,3 +5553,23 @@ function wp_generate_uuid4() {
 		mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff )
 	);
 }
+
+/**
+ * Get last changed date for the specified cache group.
+ *
+ * @since 4.7.0
+ *
+ * @param $group Where the cache contents are grouped.
+ *
+ * @return string $last_changed UNIX timestamp with microseconds representing when the group was last changed.
+ */
+function wp_cache_get_last_changed( $group ) {
+	$last_changed = wp_cache_get( 'last_changed', $group );
+
+	if ( ! $last_changed ) {
+		$last_changed = microtime();
+		wp_cache_set( 'last_changed', $last_changed, $group );
+	}
+
+	return $last_changed;
+}
\ No newline at end of file
diff --git a/src/wp-includes/general-template.php b/src/wp-includes/general-template.php
index 5b36272270..c6fc86a09d 100644
--- a/src/wp-includes/general-template.php
+++ b/src/wp-includes/general-template.php
@@ -1713,11 +1713,7 @@ function wp_get_archives( $args = '' ) {
 
 	$output = '';
 
-	$last_changed = wp_cache_get( 'last_changed', 'posts' );
-	if ( ! $last_changed ) {
-		$last_changed = microtime();
-		wp_cache_set( 'last_changed', $last_changed, 'posts' );
-	}
+	$last_changed = wp_cache_get_last_changed( 'posts' );
 
 	$limit = $r['limit'];
 
diff --git a/src/wp-includes/post.php b/src/wp-includes/post.php
index bd0c4bf6ef..6376e90bfd 100644
--- a/src/wp-includes/post.php
+++ b/src/wp-includes/post.php
@@ -4194,11 +4194,7 @@ function get_page( $page, $output = OBJECT, $filter = 'raw') {
 function get_page_by_path( $page_path, $output = OBJECT, $post_type = 'page' ) {
 	global $wpdb;
 
-	$last_changed = wp_cache_get( 'last_changed', 'posts' );
-	if ( false === $last_changed ) {
-		$last_changed = microtime();
-		wp_cache_set( 'last_changed', $last_changed, 'posts' );
-	}
+	$last_changed = wp_cache_get_last_changed( 'posts' );
 
 	$hash = md5( $page_path . serialize( $post_type ) );
 	$cache_key = "get_page_by_path:$hash:$last_changed";
@@ -4540,11 +4536,7 @@ function get_pages( $args = array() ) {
 
 	// $args can be whatever, only use the args defined in defaults to compute the key.
 	$key = md5( serialize( wp_array_slice_assoc( $r, array_keys( $defaults ) ) ) );
-	$last_changed = wp_cache_get( 'last_changed', 'posts' );
-	if ( ! $last_changed ) {
-		$last_changed = microtime();
-		wp_cache_set( 'last_changed', $last_changed, 'posts' );
-	}
+	$last_changed = wp_cache_get_last_changed( 'posts' );
 
 	$cache_key = "get_pages:$key:$last_changed";
 	if ( $cache = wp_cache_get( $cache_key, 'posts' ) ) {