Correct American English convention of pm versus p.m.
According to my research, the Chicago literary standard of how to write am, and pm, is that american convention is a.m. and p.m. The main point of the artical I read was that all of these forms are acceptable as long as the usage is consistent. Grammarly.com is now telling me to change my p.m. to pm. Which use is correct?
33 p.m. CST.