Yup.date() convert date into string without timezone after validation

Question

I using Yup with react-hook-form and have the following schema in Yup

  const validationSchema = Yup.object({
    installation: Yup.string().nullable().required("Required"),
    from_date: Yup.date()
      .max(new Date(), "Cannot use future date")
      .nullable()
      .required("Required"),
    to_date: Yup.date()
      .min(Yup.ref("from_date"), "To Date cannot be before From Date")
      .max(new Date(), "Cannot use future date")
      .nullable()
      .required("Required")
  });

When I type the date in the inputs, the validation is working perfectly but the date is being returned in the format 2021-03-31T18:30:00.000Z, however I want the date to be returned just as 2021-03-31.

I am sending the data to a Django backend server and that expects just a DateField without the timezone. How should I do this?

Is there any way to convert the date without the timezone. I can get it working if I use Yup.string() instead, but then the necessary validation would not work.

Possible Solution Idea (But need help to understand how to do it)

Can I write some custom validation in Yup. If that is possible then i could use Yup.string() and still perform the necessary validation

1. Use Yup.string()
2. Convert to date
3. Perform the necessary validation
4. Reconvert date to string
5. And return string

P.S This question has had many views but no significant comments or answers. Can I change the question formatting to make it more understandable?

Answer 1

You should write a quick function in order to change the format before to go head with further validation of yup. In order to do that you can use date-fns helper.

function parseDateString(value, originalValue) {
  const parsedDate = isDate(originalValue)
  ? originalValue  // this make sure that a value is provided
  : parse(originalValue, "yyyy-MM-dd", new Date());

  return parsedDate;
}

Than can be used in this way:

import { date, object } from "yup";

const today = new Date();

const validationSchema = Yup.object({
installation: Yup.string().nullable().required("Required"),
from_date: Yup.date()
  .transform(parseDateString)
  .max(new Date(), "Cannot use future date")
  .required("Required"),
to_date: Yup.date()
  .min(Yup.ref("from_date"), "To Date cannot be before From Date")
  .max(new Date(), "Cannot use future date")
  .required("Required")
});