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.

return [
        color[0],
        ...color.slice(1).map(x => Math.round(x * 1000) / 1000),
      ];
    }
    it("should convert RGB color for different color spaces", async () => {
      let value = await myeval(`color.convert(["RGB", 0.1, 0.2, 0.3], "T")`);
      expect(round(value)).toEqual(["T"]);
      value = await myeval(`color.convert(["RGB", 0.1, 0.2, 0.3], "G")`);
      expect(round(value)).toEqual(["G", 0.181]);
      value = await myeval(`color.convert(["RGB", 0.1, 0.2, 0.3], "RGB")`);
      expect(round(value)).toEqual(["RGB", 0.1, 0.2, 0.3]);
      value = await myeval(`color.convert(["RGB", 0.1, 0.2, 0.3], "CMYK")`);
      expect(round(value)).toEqual(["CMYK", 0.9, 0.8, 0.7, 0.7]);
    });
    it("should convert CMYK color for different color spaces", async () => {
      let value = await myeval(
        `color.convert(["CMYK", 0.1, 0.2, 0.3, 0.4], "T")`
      );
      expect(round(value)).toEqual(["T"]);
      value = await myeval(`color.convert(["CMYK", 0.1, 0.2, 0.3, 0.4], "G")`);
      expect(round(value)).toEqual(["G", 0.371]);
      value = await myeval(
        `color.convert(["CMYK", 0.1, 0.2, 0.3, 0.4], "RGB")`
      );
      expect(round(value)).toEqual(["RGB", 0.5, 0.3, 0.4]);
      value = await myeval(
        `color.convert(["CMYK", 0.1, 0.2, 0.3, 0.4], "CMYK")`
      );
      expect(round(value)).toEqual(["CMYK", 0.1, 0.2, 0.3, 0.4]);