Isolated incident with a condition

This form has a condition linked to the date. The condition is set to charge a late fee AFTER April 1, 2018.  However, 1 submission from a Bill Langer was charged the late fee on March 29th, even though the date of his submission was March 29th. None of the other submissions have had this issue.

I checked that submission and it looks like somehow their date was set to March 28th, 2019:

Likely due to their system clock being set to the incorrect date.  Since the date field is grabbing today's date, that is what was used.  The condition applied correctly in this instance.

OK - thanks. This was the only instance of this occurring. Since I have set the date field to be read only, I am wondering if requiring applicants to enter the date (but preventing them from inserting past dates) would avoid this from happening in future. 

If you want them to enter the date, but prevent them from inserting past dates, you can setup the restriction at the date settings: https://www.jotform.com/help/337-How-to-Use-the-Date-Limits-Option