Correct way to alter input field on submit

Looking at the examples here:

https://contactform7.com/dom-events/

I don’t see how to actually alter/modify an input field on submit.

I have this firing, and it does find the right input field, set the right selector for jquery, but it does not update the field. Should it, or should I be digging around in filters for this instead?

// alter date format on schedule submissions
document.addEventListener( 'wpcf7submit', function( event ) {
	// this is all the form values
	var inputs = event.detail.inputs;

	// loop on all inputs
	for ( var i = 0; i < inputs.length; i++ ) {
		// we're looking for the datepicker fields which are all "date-something"
		if(/date-*/i.test(inputs[i].name)) {
			// convert date format - we want a day name, supplied string format: '07/31/2021 03:00 PM'
			var newdate = moment(inputs[i].value).format("dddd, MMMM Do YYYY, h:mm:ss a");
			var formfield = inputs[i].name;
			jQuery('input[name="' +  formfield + '"]').val(newdate);
			alert( 'date: ' + newdate + ' form name: ' + formfield);
			
			break;
		}
	}
}, false );

For various reasons, I can’t alter the format in the datepicker plugin that’s filling the field, so I have to act on the value it puts in the input field.