Times and Daylight Savings Time
Follow AP Style when listing or writing time of day.
Times
Use figures except for noon and midnight. Do not put a "12" in front of noon. Sheila worked the noon-9:30 p.m. shift, and Daniel worked the midnight-8 a.m. shift.
Use periods between ante meridiem and post meridiem abbreviations: a.m.
and p.m.
Only use a colon to separate hours from minutes: 11 a.m., 1 p.m., 3:30 p.m.
When there are no minutes, do not use a colon and two zeros: 8:00 a.m., 11:00 a.m. to 5:00 p.m., instead it's 8 a.m., 11 a.m. to 5 p.m.
Do not repeat the abbreviation for ante meridiem and post meridiem when the time period is within the same meridiem: 9-11 a.m., 9 a.m. to 5 p.m.
Avoid such redundancies as 10 a.m. this morning, 10 p.m. tonight or 10 p.m. Monday night. Use 10 a.m. or 10 p.m. Monday, etc., as required by the norms in time element.
When you are writing the day, date and time, AP style is Thursday, May 10, at 10 p.m. EST (with commas separating each, except the time zone).
Time zones
Capitalize the full name of the time in force within a particular zone: Eastern Standard Time, Eastern Daylight Time, Central Standard Time, etc.
Lowercase all but the region in short forms: the Eastern time zone, Eastern time, Mountain time, etc.
The abbreviations GMT, BST, AST, ADT, EST, EDT, CST, CDT, MST, MDT, PST, PDT, etc., are acceptable on first reference for zones used within the United Kingdom, continental United States, Canada, and Mexico only if the abbreviation is linked with a clock reading: noon EST, 9 a.m. PST. (Do not set off the abbreviations with commas.)
Daylight Saving Time
Note the following start and end dates of daylight saving time when setting up events, especially when they are in the future.
