diff --git a/wp-includes/load.php b/wp-includes/load.php
index d72066e30..61dab0e35 100644
--- a/wp-includes/load.php
+++ b/wp-includes/load.php
@@ -182,17 +182,16 @@ function wp_maintenance() {
 }
 
 /**
- * PHP 4 standard microtime start capture.
+ * PHP 5 standard microtime start capture.
  *
  * @access private
  * @since 0.71
- * @global int $timestart Seconds and microseconds added together from when function is called.
+ * @global float $timestart Seconds from when function is called.
  * @return bool Always returns true.
  */
 function timer_start() {
 	global $timestart;
-	$mtime = explode( ' ', microtime() );
-	$timestart = $mtime[1] + $mtime[0];
+	$timestart = microtime( true );
 	return true;
 }
 
@@ -213,8 +212,8 @@ function timer_start() {
  * in most cases, you only need to echo it.
  *
  * @since 0.71
- * @global int $timestart Seconds and microseconds added together from when timer_start() is called
- * @global int $timeend Seconds and microseconds added together from when function is called
+ * @global float $timestart Seconds from when timer_start() is called
+ * @global float $timeend Seconds from when function is called
  *
  * @param int $display Use '0' or null to not echo anything and 1 to echo the total time
  * @param int $precision The amount of digits from the right of the decimal to display. Default is 3.
@@ -222,9 +221,7 @@ function timer_start() {
  */
 function timer_stop( $display = 0, $precision = 3 ) { // if called like timer_stop(1), will echo $timetotal
 	global $timestart, $timeend;
-	$mtime = microtime();
-	$mtime = explode( ' ', $mtime );
-	$timeend = $mtime[1] + $mtime[0];
+	$timeend = microtime( true );
 	$timetotal = $timeend - $timestart;
 	$r = ( function_exists( 'number_format_i18n' ) ) ? number_format_i18n( $timetotal, $precision ) : number_format( $timetotal, $precision );
 	if ( $display )
diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index ce28397a7..1c058a35b 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -1441,8 +1441,7 @@ class wpdb {
 	 * @return true
 	 */
 	function timer_start() {
-		$mtime            = explode( ' ', microtime() );
-		$this->time_start = $mtime[1] + $mtime[0];
+		$this->time_start = microtime( true );
 		return true;
 	}
 
@@ -1451,13 +1450,10 @@ class wpdb {
 	 *
 	 * @since 1.5.0
 	 *
-	 * @return int Total time spent on the query, in milliseconds
+	 * @return float Total time spent on the query, in seconds
 	 */
 	function timer_stop() {
-		$mtime      = explode( ' ', microtime() );
-		$time_end   = $mtime[1] + $mtime[0];
-		$time_total = $time_end - $this->time_start;
-		return $time_total;
+		return ( microtime( true ) - $this->time_start );
 	}
 
 	/**