EVERY schoolboy and girl should know eventually that as regards time, a.m. means ante meridian and p.m. means post meridian ie., before and after noon.

However, isn't there a strange anomaly here? When we are talking of dates in years we first have a countdown until we reach a datum, then a count up -- B.C. becomes A.D.

In hourly time, therefore, with noon as our datum, midnight must be both 12p.m. and 12a.m.

Thus, what we now refer to as 1a.m. is, in actual fact, 11 hours before noon and therefore 11a.m. -- 2a.m. is in effect 10a.m.etc.

12 noon reigns supreme and is neither a.m. nor p.m.

This, of course, makes sense of the 24 hour clock, which begins when the day begins at midnight and marches relentlessly on until the next midnight.

R BRACEWELL (Mr), Ormerod Street, Worsthorne, Burnley.