def h2hms24(h):
    """
    Convert decimal hours to hh:mm:ss, rounding value to +0h to +24h.

    """
    hm, seconds = divmod((h % 24) * 3600, 60)
    hours, minutes = divmod(hm, 60)
    return '{:02.0f}:{:02.0f}:{:02.3f}'.format(hours, minutes, seconds)