Business rule to not allow date to be in the future in a model driven app form

[Syndicate_Admin]

I'm having issues trying to implement a business rule on a date input form field in a form on a model driven app. The conditional statement logic only allows me to select a value of a single date rather than specifying that the date is the current system date, I have seen other solutions which suggest using a calculated field as the current date by setting the value to Now(), however as this evaluates at runtime it is not visible to the user before they save and submit the form. Any ideas greatly appreciated. 

[Anonymous]

@Syndicate_Admin 

Not very clear with your post, can you explain maybe with a screenshot.

Paul Zheng