Date field in form with NA (Not Applicable) selection option?

You can create a radio button field labeled as "Select Date"with value as Yes or No. If the user selects yes show a date field else show a text field with value as Not Applicable.

Thanks for the inputs, i have too many date fields in the form so need to implement one radio button for each.My requirement is In the same control user will be able to select date or NA

As per my understanding it is not possible to have not applicable on date field.you can use editable grid with the logic of radio button if multiple dates.

You could create you own custom component with exactly the same interface as the default dateTimeField but implements your own logic. Last week we did something like that with a pickerField. A radioButtonField above lets the user choose to select an existing item or create a new one. For creating a new one we replace the picker by a textField.

Then copy&paste your forms SAIL code to a text editor, search/replace the component and copy&paste it back.