Actually it has only just dawned on me that the whole AM PM thing doesn't make sense.
5pm means 5 hours after midday, ie 17.00 hrs- fine
BUT
5 am means 5 hours before midday (ante meridiem) which would be 12.00hrs minus 5 which is 7.00hrs!!!!!!!
AM could only make sense if it stood for after midnight.
Back to the padded cell for me....
At least now I have an excuse for being late.
edit-------------------------
and when is 00.00hrs?
12am? 12.00-12.00=00.00hrs
or
12pm? 12.00+12.00=24.00hrs