Question: what is nn in time?
Answer: Re: 12:00 noon/nn/ pm No abbreviation for "noon" since it is a short word already probably; however, you can use 12:00 a.m. or 12:00 midnight (or just "midnight") and 12:00 p.m. or 12:00 noon (or just "noon"). Of course, one can always go with 24 hour military time: 1200 = noon and 2400 = midnight. Bertha.