diff --git a/tryton/gui/window/view_form/view/form_gtk/calendar.py b/tryton/gui/window/view_form/view/form_gtk/calendar.py
index f1ff305d6f..5421f4a745 100644
--- a/tryton/gui/window/view_form/view/form_gtk/calendar.py
+++ b/tryton/gui/window/view_form/view/form_gtk/calendar.py
@@ -257,8 +257,9 @@ class DateTime(WidgetInterface):
                 gtk.STOCK_OK, gtk.RESPONSE_OK))
         win.set_has_separator(True)
         win.set_icon(TRYTON_ICON)
+        win.vbox.set_spacing(2)
 
-        hbox = gtk.HBox()
+        hbox = gtk.HBox(spacing=2)
         hbox.pack_start(gtk.Label(_('Hour:')), expand=False, fill=False)
         widget_hour = gtk.SpinButton(gtk.Adjustment(0, 0, 23, 1, 5), 1, 0)
         hbox.pack_start(widget_hour, expand=True, fill=True)