AM, PM

For time values in a twelve-hour system, use AM/PM preceded by a space. For example, 10:30 PM. Don’t use a.m., p.m., A.M., P.M., am, or pm.

The Today app is the only exception. In Today, use am/pm with no space. Refer to the screenshot for an example.Today app screenshot showing times of day.

Note

This guideline was updated for the Winter ’15 release and is a change from earlier practice.