Date functions

date.js

Date.prototype.formatDDMMYYYY = function () {
    return ('0' + this.getDate()).slice(-2) +
     '/' + ('0' + (this.getMonth() + 1)).slice(-2) +
     '/' + this.getFullYear();
};

Date.prototype.formatDDMMYYYYWithHMS = function () {
    return ('0' + this.getDate()).slice(-2) +
     '/' + ('0' + (this.getMonth() + 1)).slice(-2) +
     '/' + this.getFullYear() +
     ' ' + ('0' + this.getHours()).slice(-2) +
     ':' + ('0' + this.getMinutes()).slice(-2) +
     ':' + ('0' + this.getSeconds()).slice(-2);
};
        
function getDateParts(date, delim) {
    // TODO: Make this regex work with any delimiter
    // var regex = new RegExp(delim + "(\d+)/g");
    var parts = date.match(/(\d+)/g);
    return parts;
}

function getDaysInMonth(year, month) {
    return [31, (isLeapYear(year) ? 29 : 28), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month - 1];
}

function isLeapYear(year) {
    return (((year % 4 === 0) && (year % 100 !== 0)) || (year % 400 === 0));
}

function isValidDate(value, delim) {

    if (value === "" || value === null || value === undefined)
        return false;
    
    var dateParts = getDateParts(value, delim);
    
    if (dateParts === null || dateParts.length !== 3)
        return false;

    var day = parseInt(dateParts[0], 10), month = parseInt(dateParts[1], 10);
    return (dateParts[2].length == 4 && (month > 0 && month < 13) && (day > 0 && day <= getDaysInMonth(dateParts[2], month)));
}

function dateRangeContainsValue (date, start, end) {
    var startDate = parseDate(start);
    var endDate = parseDate(end);

    if (isNaN(startDate) || isNaN(endDate) || !isValidDate(date, '/')) {
        return false;
    }

    var thisDate = parseDate(date);
    
    return (thisDate >= startDate && thisDate <= endDate);
}

function dateRangeWithinBoundary (date, start, end) {
    var startDate = parseDate(start);
    var endDate = parseDate(end);

    if (isNaN(startDate) || isNaN(endDate) || !isValidDate(date, '/')) {
        return false;
    }

    var thisDate = parseDate(date);
    
    return (thisDate > startDate && thisDate < endDate);
}

function parseDate(input) {
    var parts = input.match(/(\d+)/g);
    return new Date(parts[2], parts[1] - 1, parts[0]); // months are 0-based
}

/* jQuery DateTime Utils */
jQuery.fn.isValidDate = function (delim) {
    return isValidDate($(this).val(), delim);
};

jQuery.fn.getDateParts = function (delim) {
    return getDateParts($(this).val(), delim);
};

jQuery.fn.dateRangeContainsValue = function (start, end) {
    return dateRangeContainsValue($(this).val(), start, end);
};