At Noon 12 Am or Pm?

When using a 12-hour clock, 12 pm typically refers to noon and 12 am means midnight. While most people follow this convention, technically this isn't quite right. To avoid any confusion, 12 o'clock should be written as 12 noon or 12 midnight instead.

Is 12am in the morning or night?

Midday and midnight conventions

There are no standards established for the meaning of 12am and 12pm. It is often said that 12am Monday is midnight on Monday morning and 12pm is midday. This puts all the times beginning with 12 and ending with am in the same one-hour block, similarly with those ending with pm.

Is it 12 AM or 12 AM?

12am and 12pm are both incorrect. Neither should be used. You should really pay attention to the abbreviation. "a.m." means "ante meridiem" which means "before midday" and p.m. means "post meridiem", which means "after midday".