Date and hour calculation

Hi, I have a problem with the result of my calculation with my fileds.

I draw this form:
[attachment=0]Cattura.PNG[/attachment]

I want to calculate the ammount of hours from the two time fields and write the result in a new text field.
In the total field the result will never be greater than 24 hours total.
this is a calculator of worked hours.

The date fiels are populated from a chronoform data picker.
The hour fields are populated from list of values of hour
Example:
0=00:00
0.5=00:30
1=01:00
1.5=01:30
2=02:00
etc.

I write this jquery code in the Action load javascript:

jQuery(document).ready(function (op) {
  op('#data_inizio').on('change', calc);
  op('#ora_inizio').on('change', calc);
  op('#data_fine').on('change', calc);
  op('#ora_fine').on('change', calc);
  
  function calc() {
    var JS_data_inizio = op('#data_inizio').val();
	var JS_data_fine = op('#data_fine').val();
    var JS_ora_inizio = op('#data_inizio').val();
	var JS_ora_fine = op('#data_fine').val();
	var giorno = 24;
 
    if ( JS_data_fine > JS_data_inizio ){
      op('#ore_totali').val((giorno - JS_ora_inizio) + JS_ora_fine);
    }
    else {
	  op('#ore_totali').val(JS_ora_fine - JS_ora_inizio);
}
  }
   });

This is the result:

[attachment=1]Cattura1.PNG[/attachment]

I expected to see the result equal to 9 hours.
Where i wrong?
Can you help me?

Thanks in advance.

Bye Raffaele.

Hello rafrev,
I'm not a Chrono professional, but after checking your new post, I think that the following links may help:
Date control using CFv5 date picker element
How can I format a date in the datepicker?
How can I set a default date for a datepicker?
How can I set start and end dates for a datepicker?
P.S: I'm just an automated service😉

Hi Raffaele,

You can use your browser web developer tools to help debug your JavaScript. I'd guess that the problem is with this line

op('#ore_totali').val((giorno - JS_ora_inizio) + JS_ora_fine);

The + operator works in two ways - if both the operands are numbers it adds them - it either of them are strings it concatenates them into a longer string.

Please see this StackOverFlow answer for another way to do this,

Bob