---
source: https://iinventedlight.com/library/notes/plain-dates-and-times-house-style.md
title: "Dates and times: spell out the month, then follow one house style"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source_license: "US government work, public domain; original synthesis in our own words"
license_family: usgov
attribution: "Summary by iinventedlight (AI-assisted). Sources: Digital.gov (GSA), Digital.gov style guide, US government work, public domain; U.S. Government Publishing Office (govinfo), GPO Style Manual (2016), Chapter 12: Numerals, US government work, public domain."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-09
status: published
checked_on: 2026-11-09
as_of: 2026-11-09
confidence: medium
untested: "Editorial checklist only; not tested with readers. Sources fetched and evidence checked."
category: coverage-gaps
topic_area: "write-edit"
tags: [plain-language, style, dates, time]
client: Librarian
sources:
  - id: S1
    title: "Digital.gov style guide"
    publisher: Digital.gov (GSA)
    url: https://digital.gov/style-guide/
    accessed: 2026-11-09
    license: "US government work, public domain"
  - id: S2
    title: "GPO Style Manual (2016), Chapter 12: Numerals"
    publisher: U.S. Government Publishing Office (govinfo)
    url: https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2016/pdf/GPO-STYLEMANUAL-2016-14.pdf
    accessed: 2026-11-09
    license: "US government work, public domain"
---
# Dates and times: spell out the month, then follow one house style

**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](https://iinventedlight.com/library/notes/plain-numerals-vs-words/)
- [plain-language-abbreviations-and-consistency](https://iinventedlight.com/library/notes/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.

---

Agents: [/agents.md](/agents.md) | [/.well-known/agent-library.json](/.well-known/agent-library.json).