Note: Please check JavaScript Utility Functions Note.

The following javascript function allows you to compare two dates. At this time only dd/mm/yyyy format is supported, but you can extend it very easily. The function will return -1 if first date is smaller than the second date, 1 if it is greater and 0 if both dates are equal.

/*Define the namespaces*/
var JavaScript = {};
JavaScript.Utils = {};
JavaScript.Utils.Date = {};

JavaScript.Utils.Date.Compare = function(firstDate, secondDate, format) {
                if (!(typeof firstDate === "string") || !(typeof secondDate === "string"))
                    throw "Date must be a string.";

                if (!format)
                    throw "invalid date format specified.";

                var result = -1;
                switch (format) {
                    case "dd/mm/yyyy":
                        {
                            var fdate = firstDate.match(/^(\d{2})\/(\d{2})\/(\d{4})$/i);
                            var ldate = secondDate.match(/^(\d{2})\/(\d{2})\/(\d{4})$/i);

                            if (parseInt(fdate[3]) < parseInt(ldate[3]))
                                result = -1;
                            else if (parseInt(fdate[3]) > parseInt(ldate[3]))
                                result = 1;
                            else
                                result = 0;

                            if (result == 0) {
                                if (parseInt(fdate[2]) < parseInt(ldate[2]))
                                    result = -1;
                                else if (parseInt(fdate[2]) > parseInt(ldate[2]))
                                    result = 1;
                                else
                                    result = 0;
                            }

                            if (result == 0) {
                                if (parseInt(fdate[1]) < parseInt(ldate[1]))
                                    result = -1;
                                else if (parseInt(fdate[1]) > parseInt(ldate[1]))
                                    result = 1;
                                else
                                    result = 0;
                            }
                        }
                        break;
                }

        return result;
    };