AFTER VERSION 4.0.0 

The configuration is done from the src/config.app.js  (search for optionsForDateTime )

fireadmin.mobidonia.com/docs.php#fields


BEFORE VERSION 4.0.0


In lot of cases users will want to have their own format of the Date, Time or DateTime field. 

This field uses the Bootstrap DateTime Picker https://eonasdan.github.io/bootstrap-datetimepicker/


So, in order to edit the format you will need to go in "public/assets/js/demo.js" on line  60. 

There you will find all the settings for the datetime fields


$('.datepicker').datetimepicker({
            format: 'MM/DD/YYYY',
            icons: {
                time: "fa fa-clock-o",
                date: "fa fa-calendar",
                up: "fa fa-chevron-up",
                down: "fa fa-chevron-down",
                previous: 'fa fa-chevron-left',
                next: 'fa fa-chevron-right',
                today: 'fa fa-screenshot',
                clear: 'fa fa-trash',
                close: 'fa fa-remove',
                inline: true
            }
         });

         $('.timepicker').datetimepicker({
//          format: 'H:mm',    // use this format if you want the 24hours timepicker
            format: 'h:mm A',    //use this format if you want the 12hours timpiecker with AM/PM toggle
            icons: {
                time: "fa fa-clock-o",
                date: "fa fa-calendar",
                up: "fa fa-chevron-up",
                down: "fa fa-chevron-down",
                previous: 'fa fa-chevron-left',
                next: 'fa fa-chevron-right',
                today: 'fa fa-screenshot',
                clear: 'fa fa-trash',
                close: 'fa fa-remove',
                inline: true

            }
         });