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.

function (match, nDecSep, cFlags, nWidth, nPrecision, cConvChar) {
        
        if (
          cConvChar !== "d" &&
          cConvChar !== "f" &&
          cConvChar !== "s" &&
          cConvChar !== "x"
        ) {
          const buf = ["%"];
          for (const str of [nDecSep, cFlags, nWidth, nPrecision, cConvChar]) {
            if (str) {
              buf.push(str);
            }
          }
          return buf.join("");
        }
        i++;
        if (i === args.length) {
          throw new Error("Not enough arguments in printf");
        }
        const arg = args[i];
        if (cConvChar === "s") {
          return arg.toString();
        }
        let flags = 0;
        if (cFlags) {
          for (const flag of cFlags) {
            switch (flag) {
              case "+":
                flags |= PLUS;