Using earlier Date in Forms

Using earlier Date in Forms

HI I am using ZOHO Forms and a drop down menu for the dates. Why can't I pick a date that is earlier than the current date and time in the quick pick? 

Is there a way to change the formate so it is MONTH-DAY-YEAR all in NUMBERS. Currently you can only put it in DAY- MONTH in 3LETTERS -Year in Numbers.

Thank you have a nice day

DAN