Describe the problem you are trying to fix (provide as much context as possible)

I have an issue with compare dates of certain format using .min() and .ref() methods.
Basically, what I need is comparing two dates and checking whether one is less or equal to another. There's a catch, I need to use raw() to ensure that dates are still in string format.

Let's consider this example:

const schema = Joi.object({
  from: Joi.date().format('YYYY-MM-DD').raw().required(),
  to: Joi.date().format('YYYY-MM-DD').min(Joi.ref('from')).raw().required()
})

const payload = {from: '2019-10-19', to: '2019-10-19'}

I would expect that payload would pass validation. But it doesn't. I get an error where .min() condition is not satisfied. When I remove raw() it works great, but I don't have dates as a string format.

Is there any way to achieve my goal with current API?

Which API (or modification of the current API) do you suggest to solve that problem ?

I'm using version 15.0.1 of @hapi/joi package together with 1.3.0 version @hapi/joi-date package, so it's not base package only.

Are you ready to work on a pull request if your suggestion is accepted ?

Yes, I would be glad to help.