capitalization: time references and historical periods and events

Capitalize the names of months and days, of holidays and holy days, of historical and geological periods and events, and of parliamentary sessions:

• October
• Wednesday
• Thanksgiving Day
• Passover
• Christmas
• April Fool’s Day
• the Second World War
• World War II
• the Gulf War
• the Middle Ages
• the Ice Age
• the Pleistocene Epoch
• The First Session of the Thirty-second Parliament

Similarly, capitalize the names of events recorded in sacred writings and of historical events with a strong religious dimension:

• the Flood
• the Exodus
• the Immaculate Conception
• the Crucifixion
• the Hegira
• the Crusades
• the Great Schism
• the Reformation
• the Diet of Worms
• the Second Vatican Council

However, do not capitalize the names of centuries or decades unless they are part of special names:

• the twentieth century
• the fifties

but

• the Roaring Twenties (name of an era)

Note that terms referring to events and periods are often capitalized when they refer to specific events or periods and lower cased when used in a general sense:

• the Ice Age, but the most recent ice age
• the First World War, but the two world wars
• the Quiet Revolution, but She started a revolution.
• the Crusades, but a crusade against poverty
• Stone Age tools, but He uses stone-age management techniques.

For the use of capitals with time zones, see ABBREVIATIONS: TIME ZONES.

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