Hi pdfjs team,

Please find attach a really simple pdf file to reproduce the issue.
[Date.pdf](https://github.com/mozilla/pdf.js/files/8242310/Date.pdf)
This pdf contains 4 date fields, One with a default format (dd/mm/yyyy) and the 3 others with custom formats:

    -  dd
    -  mm
    -  yyyy

The expected behavior is that whenever I fill dd field with 16 for instance, then when i focus out that field the value displayed is 16 but I get 01.

This happens for dd field and mm but it's working fine for dd/mm/yyyy and yyyy fields.

The initial values of the pdf are properly displayed, this happens only if I focus one of those fields.

Thank you for your time

Best regards.

break;
              case " ":
                flags |= SPACE;
                break;
              case "0":
                flags |= ZERO;
                break;
              case "#":
                flags |= HASH;
                break;
            }
          }
        }
        cFlags = flags;
        if (nWidth) {
          nWidth = parseInt(nWidth);
        }
        let intPart = Math.trunc(arg);
        if (cConvChar === "x") {
          let hex = Math.abs(intPart).toString(16).toUpperCase();
          if (nWidth !== undefined) {
            hex = hex.padStart(nWidth, cFlags & ZERO ? "0" : " ");
          }
          if (cFlags & HASH) {
            hex = `0x${hex}`;
          }
          return hex;
        }
        if (nPrecision) {
          nPrecision = parseInt(nPrecision.substring(1));