Present written-out dates in the order of month, day, and year. Note that a comma must follow the year if there are more words in the sentence.
On March 3, 1978, the court issued its verdict.
But when presenting dates purely with numbers (e.g., in file names or tables), follow the ISO standard for dates and write them out as year-month-day.
If only the month and year are given (e.g., March 1992), do not put a comma between them. Also, a comma is not usually needed after the year.
When writing out spans of years, use all digits.
1992–1995
When talking about something that starts in one year and ends in another (such as fiscal years), you can use a slash and abbreviate the second year.
Nothing will change in fiscal year 2013/14.
When referring to decades, never use an apostrophe.
There was a boom in the late 1990s (or 90s).
Times should be given using the 12-hour clock and be followed by a.m. or p.m. as appropriate.
Use noon or midnight instead of 12:00 p.m. or 12:00 a.m., which can be confusing.
Timezones are typically lowercased, unless it includes a proper noun (CMOS 8.90).
The meeting will be at 3:00 p.m. mountain standard time.
The meeting will be at 3:00 p.m. Pacific daylight time.
The meeting will be at 3:00 p.m. Alberta time.