Reference · Last updated May 14, 2026
Date Format Reference
Use this page when you need a quick reminder of how a date may appear in different systems.
ISO, US, UK, and readable long-form date formats.
You are copying a date into another system or form.
Ambiguous formats create avoidable mistakes.
Common formats
Planning notes
- Use ISO-style dates when you want the least ambiguity.
- Always include a time zone when the exact moment matters.
- Avoid mixing date-only and datetime values in the same workflow.
FAQ
What format is safest?
ISO-style dates are usually the least ambiguous choice.
Should I include a time zone?
Yes, whenever the exact moment matters.
Why avoid mixing formats?
Mixed formats create confusion, especially across regions or systems.