I have an ad space website, where a person can place an advert, but for a maximum of 30 days.
To do this, I have a date field with a calendar popup and collect an end date on field. So it's one field collecting both dates. I need to validate the input of the end date by comparing it to the first field (start date). I have the field validation module installed, but I'm not sure how to configure it.
How do I configure it? Or is there a better way to do this?