Convertisseur d'horodatage

À PROPOS DE CET OUTIL

Enter a Unix timestamp to see the equivalent human-readable date and time, or pick a date to get the timestamp back. Unix time counts seconds (or milliseconds, depending on the source system) elapsed since the Unix epoch of January 1, 1970 00:00:00 UTC, ignoring leap seconds — which is why it's the standard way computers store and compare dates internally. The converter also shows the value in your local timezone alongside UTC, since the same timestamp can display as a different date depending on where you are. Useful when reading server logs, debugging API responses, or working with date fields stored as numbers instead of readable strings.

COMMENT UTILISER

1. Paste a Unix timestamp (in seconds or milliseconds) into the input field.
2. View the converted date and time in both UTC and your local timezone.
3. Alternatively, pick a date and time using the date picker to get its timestamp.
4. Check whether the tool detected your value as seconds or milliseconds — a 13-digit number is milliseconds, a 10-digit number is seconds.
5. Copy the converted value you need.
6. Repeat for other timestamps found in logs or API payloads.

CAS D'USAGE COURANTS

• A backend developer reading raw server logs converts a createdAt field storing 1735689600 into a readable date.
• Someone debugging a scheduled job checks whether a cron timestamp matches the expected execution time in their timezone.
• A support engineer investigating a bug report converts the timestamp from an error report to see exactly when it occurred.
• A data analyst working with a CSV export full of epoch timestamps spot-checks a few rows before running a bulk conversion script.
• A developer testing token expiration logic checks what date a JWT's "exp" claim actually corresponds to.

CONSEILS ET ERREURS COURANTES

• Unix timestamps in seconds are 10 digits (until the year 2286); if your number has 13 digits, it's in milliseconds, and mixing the two up is the most common conversion mistake.
• Unix time does not account for leap seconds, so it's not perfectly astronomically accurate, though this almost never matters for everyday applications.
• Timestamps are timezone-agnostic by definition — the number itself represents a fixed instant in UTC; only its display changes with timezone.
• Watch for the "Year 2038 problem": systems that store Unix time as a signed 32-bit integer overflow on January 19, 2038, which still affects some older or embedded systems.

AUTRES QUESTIONS

What's the difference between a timestamp in seconds vs milliseconds?

JavaScript's Date.now() and many web APIs use milliseconds since the epoch, while Unix/POSIX time and many backend languages default to seconds — a 10-digit number is seconds, 13 digits is milliseconds.

What exactly is the Unix epoch?

It's a fixed reference point, midnight UTC on January 1, 1970; all Unix timestamps represent the number of seconds (or ms) elapsed since that instant, with negative numbers representing dates before it.

Does Unix time handle leap seconds?

No, standard Unix time ignores leap seconds entirely, which means it drifts very slightly from true UTC over decades — a detail relevant to astronomers, not typical app development.

Why does converting the same timestamp give different results on different computers?

Only the UTC value is fixed; the human-readable local time shown depends on the timezone setting of the browser or system doing the conversion, so the same timestamp reads differently in Tokyo vs New York.

GUIDES ASSOCIÉS

OUTILS ASSOCIÉS