diff --git a/source/ubl-settings-datetime.c b/source/ubl-settings-datetime.c
index 6e30621..d59276a 100644
--- a/source/ubl-settings-datetime.c
+++ b/source/ubl-settings-datetime.c
@@ -234,7 +234,7 @@ void yon_interface_update(main_window *widgets){
     GDateTime *datetime = g_date_time_new_now_local();
     char *time = g_date_time_format(datetime,"%H %M");
     char *date = g_date_time_format(datetime,"%Y.%m.%d");
-    gtk_calendar_select_month(GTK_CALENDAR(widgets->DateCalendar),g_date_time_get_month(datetime),g_date_time_get_year(datetime));
+    gtk_calendar_select_month(GTK_CALENDAR(widgets->DateCalendar),g_date_time_get_month(datetime)-1,g_date_time_get_year(datetime));
     gtk_calendar_select_day(GTK_CALENDAR(widgets->DateCalendar),g_date_time_get_day_of_month(datetime));
 
     if (!yon_char_is_empty(time)){