Description: SetCulture

Link: http://www.codekeep.net/snippets/e88681be-1e17-41fc-bce3-41675ce87f97.aspx

public void SetCulture(string siteUrl)
        {
            try
            {
                CultureAndRegionInfoBuilder.Unregister("pl-PL");
            }
            catch { }

            CultureAndRegionInfoBuilder carib = new CultureAndRegionInfoBuilder("pl-PL", CultureAndRegionModifiers.Replacement);
            carib.LoadDataFromCultureInfo(new CultureInfo("lt-LT"));
            carib.LoadDataFromRegionInfo(new RegionInfo("lt"));
            carib.GregorianDateTimeFormat.ShortDatePattern = "yyyy-MM-dd";
            carib.Register();

            CultureInfo ci = new CultureInfo("pl-PL");

            SPSecurity.RunWithElevatedPrivileges(delegate()
            {
                using (SPSite site = new SPSite(siteUrl))
                {
                    using (SPWeb web = site.RootWeb)
                    {
                        site.AllowUnsafeUpdates = true;
                        web.AllowUnsafeUpdates = true;

                        web.Locale = ci;
                        web.Update();
                    }
                }
            });
        }