Microsoft® Manual of Style, Fourth Edition

Time and place

To globalize information for time and place, use the guidelines in the following table.

Guideline	More information
Use international time formats.	Do not use A.M. and P.M. notation unless you have no other choice. Use 24-hour time format.
If you give a time for an event, include the time zone and the corresponding GMT zone.	Microsoft style 13:00 Eastern Time (UTC5)
Begin calendars on Monday, not Sunday.	This is the custom in much of the world.
Spell out names of months.	Use the format month dd, yyyy. Microsoft style January 5, 2011 Do not use numbers to represent months. For example, do not use 6/12/2011. This example could be read in different parts of the world as June 12, 2011, or as December 6, 2011.
Do not refer to seasons unless ...