I am not sure what the date format is supposed to be (would be helpful if that was a tool tip). If you start typing a standard format such as 11.25.74 or 11/25/74 it states the date format is invalid.

If you use the calendar to select the date, it starts at December 2016 and takes considerable time to scroll to the correct month. It is also hard to use on an Ipad or tablet.

My suggestion would be to allow a more standard date for people to enter and give an example of what is expected so they are not trying multiple times and getting frustrated.