diff --git a/src/wp-includes/general-template.php b/src/wp-includes/general-template.php
index e96f0f7c37429..54eaf0b244a10 100644
--- a/src/wp-includes/general-template.php
+++ b/src/wp-includes/general-template.php
@@ -2305,8 +2305,9 @@ function get_calendar( $initial = true, $display = true ) {
 		$thismonth = current_time( 'm' );
 	}
 
-	$unixmonth = mktime( 0, 0, 0, $thismonth, 1, $thisyear );
-	$last_day  = gmdate( 't', $unixmonth );
+	$current_day = current_time('j');
+	$unixmonth   = mktime( 0, 0, 0, $thismonth, $current_day, $thisyear );
+	$last_day    = gmdate( 't', $unixmonth );
 
 	// Get the next and previous month and year with at least one post.
 	$previous = $wpdb->get_row(