Human-readable expire in user.present

According to user.present documentation the expire property of user.present should be specified as an integer as

Date that account expires, represented in days since epoch (January 1, 1970)

To make it more human-readable I want to be able to specify it as a string with an ISO 8601 date (e.g. "2020-01-27").

Instead of:

foo-expires:
  user.present:
    - name: foo
    - expire: 18288

I would like to be able to have:

foo-expires:
  user.present:
    - name: foo
    - expire: 2020-01-27

That would make it much easier to understand when a user expires.