Times
Use lowercase and periods for “a.m.” and “p.m.”
When referring to time, use a colon only to separate minutes from the hour.
When writing out times, use a.m. or p.m., lower case with periods and a space separating them from the time.
Example: 2 a.m.; 4:10 p.m.
Also use noon and midnight, not 12 noon or 12 midnight.