Signify a.m. or p.m. and the relevant time zone whenever referring to time.

To determine the relevant time zone, use the time zone most relevant to your audience; if your audience spans multiple time zones, use the time zone where the event is being played: the Cubs game is scheduled to begin at 3:05 p.m. CT

The use of “Daylight” and “Standard” is never necessary when referring to time zones.

Avoid “midnight” as it can create confusion, but favor noon over “12 p.m.” for the same reason. If the use of midnight is unavoidable, then it ends the day.