diff --git a/addons/hr_holidays/models/hr_leave.py b/addons/hr_holidays/models/hr_leave.py
index 68dd2255e60..f597cdc9cb4 100644
--- a/addons/hr_holidays/models/hr_leave.py
+++ b/addons/hr_holidays/models/hr_leave.py
@@ -303,6 +303,7 @@ class HolidaysRequest(models.Model):
         tz = self.env.user.tz if self.env.user.tz and not self.request_unit_custom else 'UTC'  # custom -> already in UTC
         self.date_from = timezone(tz).localize(datetime.combine(self.request_date_from, hour_from)).astimezone(UTC).replace(tzinfo=None)
         self.date_to = timezone(tz).localize(datetime.combine(self.request_date_to, hour_to)).astimezone(UTC).replace(tzinfo=None)
+        self._onchange_leave_dates()
 
     @api.onchange('request_unit_half')
     def _onchange_request_unit_half(self):