Midnight vs. Noon Formatting
Noon and midnight are clearer than 12 AM/12 PM because readers can interpret the numeric labels inconsistently. Microsoft and Australian Government style guidance recommend using the words, and Microsoft notes that midnight begins the new day.
For clarity, write “noon” (or “midday”) and “midnight” instead of relying on 12 AM and 12 PM. When midnight is tied to a date or deadline, make the day boundary explicit.
Key details
Important caveats
Date Boundary
When a deadline is at midnight, include enough date context to make the intended boundary clear.
Further guidance
Clarity Rule
Prefer the words “noon”/“midday” and “midnight” when clarity matters instead of relying on 12 AM or 12 PM.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Date and time terms — Microsoft Style Guide (opens in a new tab)Microsoft · Microsoft house style for AM/PM and human-facing time notation
- Dates and time — Australian Government Style Manual (opens in a new tab)Australian Government Style Manual · Australian Government guidance for day–month–year dates, ordinal dates, decades, centuries, time zones, and en-dash spacing in date/time spans