rodneCislo.js

// PHP verze zde: https://phpfashion.com/jak-overit-platne-ic-a-rodne-cislo


function checkDate(m, d, y) {
    //  discuss at: http://phpjs.org/functions/checkdate/
    // original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // improved by: Pyerre
    // improved by: Theriault
    //   example 1: checkdate(12, 31, 2000);
    //   returns 1: true
    //   example 2: checkdate(2, 29, 2001);
    //   returns 2: false
    //   example 3: checkdate(3, 31, 2008);
    //   returns 3: true
    //   example 4: checkdate(1, 390, 2000);
    //   returns 4: false

    return m > 0 && m < 13 && y > 0 && y < 32768 && d > 0 && d <= (new Date(y, m, 0)).getDate();
}

function birthNumber() {
    return {
        require: 'ngModel',
        link: function (scope, elm, attrs, ctrl) {

            ctrl.$validators.birthNumber = function (modelValue, viewValue) {
                if (ctrl.$isEmpty(modelValue)) {
                    // consider empty models to be valid
                    return true;
                }

                var regex = /^\s*(\d\d)(\d\d)(\d\d)[ /]*(\d\d\d)(\d?)\s*$/;
                var match = regex.exec(viewValue);

                if (match) {
                    var year = parseInt(match[1]);
                    var month = parseInt(match[2]);
                    var day = parseInt(match[3]);
                    var ext = parseInt(match[4]);
                    var c = match[5];

                    var mod;

                    if (c === '') {
                        year += year < 54 ? 1900 : 1800;
                    } else {
                        mod = ('' + year + month + day + ext) % 11;
                        if (mod === 10) { mod = 0; }
                        if (mod !== parseInt(c)) {
                            return false;
                        }

                        year += year < 54 ? 2000 : 1900;
                    }

                    if (month > 70 && year > 2003) {
                        month -= 70;
                    } else if (month > 50) {
                        month -= 50;
                    } else if (month > 20 && year > 2003) {
                        month -= 20;
                    }

                    return checkDate(month, day, year);
                }

                // it is invalid
                return false;
            };
        }
    };
}

var ext = parseInt(match[4]); is not correct.
var ext = parseInt(match[4] + match[5]); this is correct