def enough_time(dates, day_delta):
    """Change detection requires a minimum amount of time (as specified by
    day_delta).

    This function, like `enough_samples` improves readability of logic
    that performs this check.

    Args:
        dates: list of ordinal day numbers relative to some epoch,
            the particular epoch does not matter.
        day_delta: minimum difference between time at meow_ix and most
            recent observation.

    Returns:
        bool: True if the represented time span is greater than day_delta
    """
    return dates[-1] - dates[0] >= day_delta
