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.

}
        nDecSep = nDecSep ? nDecSep.substring(1) : "0";
        const separators = {
          0: [",", "."],
          1: ["", "."],
          2: [".", ","],
          3: ["", ","],
          4: ["'", "."],
        };
        const [thousandSep, decimalSep] = separators[nDecSep];
        let decPart = "";
        if (cConvChar === "f") {
          if (nPrecision !== undefined) {
            decPart = Math.abs(arg - intPart).toFixed(nPrecision);
          } else {
            decPart = Math.abs(arg - intPart).toString();
          }
          if (decPart.length > 2) {
            decPart = `${decimalSep}${decPart.substring(2)}`;
          } else if (cFlags & HASH) {
            decPart = ".";
          } else {
            decPart = "";
          }
        }
        let sign = "";
        if (intPart < 0) {
          sign = "-";
          intPart = -intPart;
        } else if (cFlags & PLUS) {