var cultureInfo = (CultureInfo)Thread.CurrentThread.CurrentCulture.Clone();
            cultureInfo.DateTimeFormat.ShortDatePattern = "yyyy-MM-dd";
            Thread.CurrentThread.CurrentCulture = cultureInfo;

            const string path = @"C:\Users\piotr\Downloads\sample (1).pdf";

            var bounds = new RectangleF(0, 0, 100, 100);
            var pdfDoc = new PdfLoadedDocument(path);

            foreach (PdfLoadedPage page in pdfDoc.Pages)
            {
                var redaction = new PdfRedaction(bounds);
                page.AddRedaction(redaction);
            }

            pdfDoc.Redact();

            var shortDatePattern = Thread.CurrentThread.CurrentCulture.DateTimeFormat.ShortDatePattern;
            Debug.Assert(shortDatePattern == "yyyy-MM-dd");