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.

it("should test language", async () => {
      let value = await myeval(`app.language`);
      expect(value).toEqual("ENU");
      value = await myeval(`app.language = "hello"`);
      expect(value).toEqual("app.language is read-only");
    });
    it("should test platform", async () => {
      let value = await myeval(`app.platform`);
      expect(value).toEqual("UNIX");
      value = await myeval(`app.platform = "hello"`);
      expect(value).toEqual("app.platform is read-only");
    });
  });
  describe("AForm", function () {
    beforeAll(function () {
      sandbox.createSandbox({
        appInfo: { language: "en-US", platform: "Linux x86_64" },
        objects: {},
        calculationOrder: [],
        dispatchEventName: "_dispatchMe",
      });
    });
    describe("AFExtractNums", function () {
      it("should extract numbers", async () => {
        let value = await myeval(`AFExtractNums("123 456 789")`);
        expect(value).toEqual(["123", "456", "789"]);
        value = await myeval(`AFExtractNums("123.456")`);
        expect(value).toEqual(["123", "456"]);
        value = await myeval(`AFExtractNums("123")`);
        expect(value).toEqual(["123"]);