Year

1. Use figures, without commas: "1975." Use an "s" without an apostrophe to indicate spans of decades or centuries: the 1970s, the 1800s. Years are the lone exception to the general rule in numerals that a figure is not used to start a sentence.
   
   ie. 1976 was a very good year.
2. When referring to a date within the current year, it is not necessary to state the year. References such as "last year" or "next year" also are adequate without stating the year.
3. When using a specific date, the year should be preceded and followed by a comma.
   
   ie. On Sept. 11, 2001, tragedy struck this country.