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Answer: Write dates as Month Day, Year with a four-digit year, not in numeric form. For users in some other countries, 01/11/2018 would mean November 1, not January 11.

Digital.gov

• Use the expanded form of Month Day, Year (February 16, 2022) and the full four-digit year for specific dates.

GPO Style Manual

• June 29, 1985 (not June 29th, 1985); June 1985 (not June, 1985).

Where the guides differ

| Style | GPO | Digital.gov | |---|---|---| | Ordinal on a date | June 29, 1985 (not June 29th) | November 23rd | | Time of day | 10 p.m. (not 10:00 p.m.) | 4:00 pm |

Avoid redundancies, such as "10 am this morning."

See also

• plain-numerals-vs-words
• plain-language-abbreviations-and-consistency

Claims

• id: C1 claim: Digital.gov uses the expanded Month Day, Year form. source: S1 evidence: "Use the expanded form of Month Day, Year"

• id: C2 claim: Digital.gov uses a four-digit year for specific dates. source: S1 evidence: "For specific dates, use the full, four-digit year"

• id: C3 claim: GPO drops ordinals on dates. source: S2 evidence: "June 29, 1985 (not June 29th, 1985)"

• id: C4 claim: GPO writes 10 p.m., not 10:00 p.m. source: S2 evidence: "10 o’clock or 10 p.m."

Sources

• [S1] Digital.gov style guide. Digital.gov (GSA). https://digital.gov/style-guide/ . License: US government work, public domain. Accessed 2026-11-09.

• [S2] GPO Style Manual (2016), Chapter 12: Numerals. U.S. Government Publishing Office (govinfo). https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2016/pdf/GPO-STYLEMANUAL-2016-14.pdf . License: US government work, public domain. Accessed 2026-11-09.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted). Sources: US federal government works (GSA, GPO, SEC, CDC), public domain in the United States; third-party quotations inside those works were not used. Text was condensed and changed from the originals.

@misc{iil_note_dnynr7md,
  author = {{iinventedlight}},
  title = {{Dates and times: spell out the month, then follow one house style}},
  howpublished = {iinventedlight Library},
  year = {2026},
  date = {2026-11-09},
  url = {https://iinventedlight.com/library/notes/plain-dates-and-times-house-style/},
  note = {Permanent ID iil:note:dnynr7md. License: CC-BY-4.0.},
}

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