DAYS OF THE WEEK AND MONTH, FESTIVALS AND HISTORIC DAYS
The proper names of the days of the week and of the months of the year should always begin with a capital. This rule is amplified to include the days of feasts and fasts, festivals and holidays, whether they are for religious or civic observance, as:
- Arbor Day
- Ascension
- Bank Holiday
- Christmas
- Decoration Day
- Easter
- Fast Day
- Fourth of July
- Good Friday
- Labor Day
- Lady Day
- New Year's
- Thanksgiving
- Whitsunday
- Whitsuntide
Appellations attached to historic days, even when they are of merely temporary importance, as Black Friday, must be rated as proper names and should take a capital.
Do not capitalize O'Clock in any lower-case text that seems to call for some form of modified display; always make it o'clock. This remark applies also to such names as John o' Groat, Tarn o' Shanter, etc.: in all names so compounded the o' should be small and separated from the following word.
TITLES OF BOOKS, PERIODICALS, PLAYS, AND PICTURES
The title of every book, periodical, play, or picture that is mentioned in the text should always begin
