1941- 1946 (as opposed to use of a hyphen)
If an editor is using a typewriter to produce copy, the en dash is created by typing the hyphen key twice. Do not type a space on either side of the dash.
Change in thoughtUse a dash to indicate an abrupt change in thought or expression or as a form of parenthetic expression.
The Odor Eaters' comedy routine--there's no delicate was of saying this--stunk.
EmphasisUse a dash to indicate an emphatic or summarizing thought at the end of a sentence. The dash may be a more visible form of punctuation than the colon in such circumstances.
I'm definitely going to go on that Barbershop trip to England--maybe.
Unfinished statementsUse a dash to indicate an unfinished statement of dialogue, especially one that is abruptly ended.
Our director abruptly stopped the chorus and spoke through clenched teeth, "If you guys don't slow down, I'm going to--"
Note that when a dash comes at the end of an unfinished statement, no period is used because the sentence is not completed.
Introductory items in a seriesUse a dash after a series of items that begin a sentence when the series functions as a summary.
Precise vowel matching, evocative facial expressions, creative interpretation--all these earned Fortuosity the gold medal.
Series with commasUse dashes to set off a phrase containing a series of words that must be separated by commas.
John described the costume--black shoes, black pants, white shirt, red vest, red tie--that will be used in the performance.