Noon is the time exactly halfway through the day , written 12.00 or 12:00 in the 24-hour clock and 12:00 pm in the 12-hour clock . Midday also means noon , although this also means around noon , or very early afternoon . With 12-hour time notation , most authorities recommend avoiding confusion by using `` noon , '' `` 12 noon , '' or `` 12:00 noon . ''