Close Form automatically if date not equal to current date

Question

Dear all please help me with this, I have a windows Form where I have a datetimepicker which by default takes a current date. But if the user change the date from the system, how to ensure that it is not current date and if it detects that current date is not true close the Form automatically. 

I will be always grateful to you all for helping me with this!! Tons of thanks in advance.