diff --git a/htdocs/comm/action/index.php b/htdocs/comm/action/index.php
index e05b74fa9a4..2187df8caf4 100644
--- a/htdocs/comm/action/index.php
+++ b/htdocs/comm/action/index.php
@@ -316,7 +316,7 @@ if (empty($mode) || $mode == 'show_month') {
 	$next_month = $next['month'];
 
 	$max_day_in_prev_month = date("t", dol_mktime(12, 0, 0, $prev_month, 1, $prev_year, 'gmt')); // Nb of days in previous month
-	$max_day_in_month = date("t", dol_mktime(12, 0, 0, $month, 1, $year)); // Nb of days in next month
+	$max_day_in_month = date("t", dol_mktime(12, 0, 0, $month, 1, $year, 'gmt')); // Nb of days in next month
 	// tmpday is a negative or null cursor to know how many days before the 1st to show on month view (if tmpday=0, 1st is monday)
 	$tmpday = -date("w", dol_mktime(12, 0, 0, $month, 1, $year, 'gmt')) + 2; // date('w') is 0 fo sunday
 	$tmpday += ((isset($conf->global->MAIN_START_WEEK) ? $conf->global->MAIN_START_WEEK : 1) - 1);