before

Ensures the value of field under validation is before a given date.

This method will import isBefore method from date-fns.

const rules = {
  confCall: 'before:2018-11-20'
}

// or
const rules = {
  confCall: [
    rule('before', new Date().setDate(new Date().getMonth() + 12))
  ]
}

For customized build, you can import this rule as follows.

import { before } from 'indicative/builds/validations'