checkdateformat

function isValidDate(dateString)
        {
            // First check for the pattern
            var regex_date = /^\d{4}\-\d{1,2}\-\d{1,2}$/;

            if(!regex_date.test(dateString))
            {
                return false;
            }

            // Parse the date parts to integers
            var parts   = dateString.split("-");
            var day     = parseInt(parts[2], 10);
            var month   = parseInt(parts[1], 10);
            var year    = parseInt(parts[0], 10);

            // Check the ranges of month and year
            if(year < 1000 || year > 3000 || month == 0 || month > 12)
            {
                return false;
            }

            var monthLength = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ];

            // Adjust for leap years
            if(year % 400 == 0 || (year % 100 != 0 && year % 4 == 0))
            {
                monthLength[1] = 29;
            }

            // Check the range of the day
            return day > 0 && day <= monthLength[month - 1];
        }
        
        https://stackoverflow.com/questions/6177975/how-to-validate-date-with-format-mm-dd-yyyy-in-javascript