Number of days between 2 dates in Python and JavaScript

    def day_diff(oldest, newest):
        """
        :param datetime oldest:
        :param datetime newest:
        """
        if oldest > newest:
            return 0
        delta = newest - oldest
        return delta.days

    function day_diff(first, second) {
        return Math.round((second-first)/(1000*60*60*24));
    }