Question about using `DateFromSelf` in `effect/Schema` transformation

import { ParseResult, Schema as S } from "effect";

export const DumbInputSchema = S.Struct({
  id: S.String,
  name: S.String,
  value: S.String,
  lastModified: S.Date,
});

export const DumbOutputSchema = S.Struct({
  id: S.String,
  name: S.String,
  value: S.String,
});

export const inputToOutput = S.transformOrFail(
  S.Struct({
    ...DumbInputSchema.fields,
    /**
     * without this, the transform fails with:
     *  Types of property 'lastModified' are incompatible.
    Type 'Date' is not assignable to type 'string'.ts(2345)
     */
    lastModified: S.DateFromSelf,
  }),
  DumbOutputSchema,
  {
    decode: (input) => {
      return ParseResult.succeed({
        ...input,
      });
    },
    encode: (output, _, ast) => {
      return ParseResult.fail(
        new ParseResult.Forbidden(ast, output, "encoding not supported"),
      );
    },
  },
);

export const decodeInputToOutput = S.decodeSync(inputToOutput);

const input = DumbInputSchema.make({
  id: "test-id",
  name: "Test Name",
  value: "Test Value",
  lastModified: new Date("2024-01-01T00:00:00.000Z"),
});

const output = decodeInputToOutput(input);