diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 60229ee10b..3b8ed27b20 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -74,7 +74,8 @@ function current_time( $type, $gmt = 0 ) {
 }
 
 /**
- * Retrieve the date in localized format, based on timestamp.
+ * Retrieve the date in localized format, based on a sum of Unix timestamp and
+ * timezone offset in seconds.
  *
  * If the locale specifies the locale month and weekday, then the locale will
  * take over the format for the date. If it isn't, then the date format string
@@ -84,15 +85,16 @@ function current_time( $type, $gmt = 0 ) {
  *
  * @global WP_Locale $wp_locale
  *
- * @param string   $dateformatstring Format to display the date.
- * @param bool|int $unixtimestamp    Optional. Unix timestamp. Default false.
- * @param bool     $gmt              Optional. Whether to use GMT timezone. Default false.
+ * @param string   $dateformatstring      Format to display the date.
+ * @param int|bool $timestamp_with_offset Optional. A sum of Unix timestamp and timezone offset in seconds.
+ *                                        Default false.
+ * @param bool     $gmt                   Optional. Whether to use GMT timezone. Default false.
  *
  * @return string The date, translated if locale specifies it.
  */
-function date_i18n( $dateformatstring, $unixtimestamp = false, $gmt = false ) {
+function date_i18n( $dateformatstring, $timestamp_with_offset = false, $gmt = false ) {
 	global $wp_locale;
-	$i = $unixtimestamp;
+	$i = $timestamp_with_offset;
 
 	if ( false === $i ) {
 		$i = current_time( 'timestamp', $gmt );
@@ -147,7 +149,7 @@ function date_i18n( $dateformatstring, $unixtimestamp = false, $gmt = false ) {
 	 *
 	 * @param string $j          Formatted date string.
 	 * @param string $req_format Format to display the date.
-	 * @param int    $i          Unix timestamp.
+	 * @param int    $i          A sum of Unix timestamp and timezone offset in seconds.
 	 * @param bool   $gmt        Whether to convert to GMT for time. Default false.
 	 */
 	$j = apply_filters( 'date_i18n', $j, $req_format, $i, $gmt );