Commas in Dates and Addresses
The Comma
Rulebase Summary
In dates, use a comma after the day of the month and after the year when the date appears mid-sentence. If only the month and year are given, commas may be used or omitted. In military-style dates (12 September), no commas are used. In addresses, use a comma after each element (street, city, state) but not between the state and ZIP Code. Do place a comma after the ZIP Code if the sentence continues.
Examples
A. On June 14 2023 I received the letter at my home.
A. On June 14, 2023, I received the letter at my home.
Commas after the day and after the year mid-sentence.
A. The office was at 200 Main Street Denver Colorado 80202 at the time.
A. The office was at 200 Main Street, Denver, Colorado 80202, at the time.
Commas between address elements; none before ZIP.
Transcript Notes
When the sentence continues after the state name, surround the state with commas. When a ZIP code follows the city or state, do not separate it — it forms a unit with the element it follows. If the sentence continues after the ZIP code, surround the state-and-ZIP-code unit with commas.
For dates with month, day, and year: if the sentence continues, surround the year with commas. When only the month and year are given (no day), the comma between them is optional — the trend is to omit it, but consistency is key.
When the city-state unit acts as a direct adjective before a noun, two rules conflict: always surround the state with commas vs. never put a comma between an adjective and the noun it modifies. Either approach is acceptable — pick one and be consistent.
Style Guide References (9)
Morson's
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