How Do I Compare Today's Date With A Posted Date And Default To Today's Date If The Posted Date Is In The Past

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

    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 posteddate = new Date(dateString);
    if (todaysdate > posteddate) {
        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];
}