ISO vs US vs EU Date Formats: How to Convert Between Them
01/02/2026 means January 2nd in the US and February 1st almost everywhere else. Date format ambiguity causes real mistakes in scheduling, contracts, and data entry - here is how the main formats differ, and a free way to convert between them.
Why the same date looks different in different formats
| Format | Order | Example (Jan 2, 2026) |
|---|---|---|
| ISO 8601 | YYYY-MM-DD | 2026-01-02 |
| US | MM/DD/YYYY | 01/02/2026 |
| EU | DD/MM/YYYY | 02/01/2026 |
| Unix timestamp | seconds since 1970-01-01 UTC | 1767312000 |
ISO 8601 is the only one of these that sorts correctly as plain text and is unambiguous regardless of the reader's country, which is why most databases, APIs, and programming languages default to it internally even when displaying a different format to users.
Where format mismatches cause real problems
- Scheduling across countries - a meeting invite dated "03/04" reads as March 4th in the US and April 3rd in most of the rest of the world.
- Data entry into spreadsheets or databases - importing a CSV with the wrong assumed format silently swaps day and month for any date where both are 12 or under.
- Legal and financial documents - contracts and invoices dated ambiguously can create real disputes over deadlines.
How to convert a date between formats online for free
- Open the Date Format Converter.
- Pick any date using the date picker.
- See it instantly converted into six formats at once: ISO 8601, US, EU, long-form, short-form, and Unix timestamp.
- Copy whichever format you need with one click.
Questions
Frequently asked
What is a Unix timestamp and why does it exist?
It is the number of seconds elapsed since January 1, 1970 (UTC) - a single number that sorts and compares easily, which is why it is widely used internally in programming and databases even though it is not human-readable.
Why does ISO 8601 sort correctly as plain text and US/EU formats do not?
Because ISO 8601 orders components from largest (year) to smallest (day), sorting the text alphabetically also sorts it chronologically - MM/DD/YYYY and DD/MM/YYYY do not have that property.
Is this date format converter free?
Yes, completely free with no sign-up and no limit on how many dates you convert.
Does it work with dates before 1970?
ISO, US, EU, and written formats work for any date; the Unix timestamp format specifically represents time relative to January 1, 1970, so dates before that produce a negative timestamp.