Ensure end date is after start date

I have a table with a bunch of columns plus a start date and an end date for an event. When i plug in a start date, i want to ensure the end date is that day or later. An end date should never be before the start date. How can I do this?

Dear @Matt_Williams_technovangelist,

My approach would be to use the conditional formating between the start date and end date.
In this way if the end date is smaller then the start date it will be formated accordingly your format setting.

Kind regards,