12:00 am has no meaning

Sometimes you go through life with a little blind spot. I have, for as long as I can remember, never been sure whether to put am or pm after 12:00 noon or 12:00 midnight if I am not using the 24 clock which of course I normally do to avoid any confusion.

It never occurred to me that appending am or pm to midday or midnight made no sense whatsoever. Am I the only one?

It took a Google Search and this Greenwich Meantime site for the penny to drop.

A.M. and P.M. start immediately after Midnight and Noon (Midday) respectively. This means that 00:00 A.M. or 00:00 P.M. (or 12:00 A.M. and 12:00 P.M.) have no meaning.

Credit: GreenwichMeanTime.com